Thứ Bảy, 4 tháng 2, 2017

Real World Comparison of a S85 to an 85D Efficiency part 1

  • Mar 7, 2015
    breser
    Today I drove from my home in North Bend, WA to the Coeur d'Alene, ID SuperCharger. Joining me in this was another TMC member ThortsMD who drove his Model S 85 with me. We met up at my house a little before 7am. Before we set off we made some effort to try to eliminate as many variables (i.e. differences) as possible.

    State of Charge

    His car is a fairly early (VIN in the 6XXX range) and has some battery degradation so we couldn't use percentage of charge to compare even though they have the same size battery. We also couldn't directly use rated range to compare since an S85 and 85D have different rated ranges. So we used the combined EPA kWh/100 miles number to estimate charge in the battery. He had 184 rated miles which when multiplied by the 0.38 kWh/mile comes out to 69.92 kWh in his pack. An 85D uses 0.34 kWh/mile which comes out to 205.6 miles so I charged my battery to 206 miles of range. It's hard to say if this is a valid way of calculating the energy in the battery. It's also not really clear if this is important.

    Ultimately we gave up on even bothering with this after the first leg. The S85 had a A pack and charged slower and we had breakfast and it was going to be pain to try and manage this so we just didn't worry about it much on all the other legs.

    Other Driving Parameters

    We agreed to use 70�F as the climate setting. We agreed to drive at 73 mph excepting for areas where the speed limit drops and there's some construction through the pass. Both cars have 19" wheels. Mine has the Michelin Primacy tires, his had Goodyear Eagles. I had my fianc�e along, so I had an extra passenger. I have tinted windows, he does not (which might some difference in the warmer part of the afternoon). Both cars have air suspension (but I didn't think to ask what his settings were for lowering the car). Neither car used range mode in any of the driving we did.

    For the legs to Coeur d'Alene the S85 was in the lead and the 85D followed with TACC. For the legs back to North Bend we reversed things and the S85 followed the 85D.

    Data

    We probably didn't do the best job keeping track of data. I did have VisibleTesla running for my car which provides a lot more data but ThortsMD had never used it and given the recent access issues with it we didn't bother to try getting it working for his car. Unfortunately we didn't track exactly the same info however we both kept track of the most important bits which was the kWh used and the Wh/mile. I kept track of the distance of the drives and the rough temperature during the drive.

    Leg Distance in miles
    		 Temperature S85 kWh Used S85 Wh/mile 85D kWh Used 85D Wh/mile
    North Bend to Ellensburg 77.5 50�F leaving North Bend (not entirely sure this is accurate but it's what the car said), 34�F at summit, 37�F at Ellensburg 28.7* 380* 30.8 397
    Ellensburg to Ritzville 114.0 46�F leaving Ellensburg, 54�F arriving Ritzville 40.3 353 41.6 365
    Ritzville to Coeur d'Alene 92.2 59�F leaving Ritzville, 59�F arriving Coeur d'Alene 29.8 323 31.1 337
    Coeur d'Alene to Ritzville 91.9 61�F leaving Coeur d'Alene, 63�F Arriving Ritzville 27.8� 303 30.7 334
    Ritzville to Ellensburg 113.9 67�F leaving Ritzville, 62�F arriving Ellensburg 35.2� 309 38.4 338
    Ellensburg to North Bend 77.3 59�F leaving Ellensburg, 48�F arriving North Bend 23.9 310 25.9 336
    Total 566.8
    		185.9� 329 198.5 350
    * This number should be slightly lower since ThortsMD missed resetting the trip and didn't charge at my house before leaving. He realized this roughly a third of a mile into our trip. So to some extent this first leg is suspect. However, since I hadn't driven any since the previous day I think some of the warming up of the car I did by way of running the climate system in my garage before leaving was included in this number. So I think this whole leg is suspect.

    � ThortsMD apparently didn't write this information down. I've calculated these by using kWh = (Wh/mile * miles) / 1000. Unfortunately the miles are from the 85D and not the S85 so it's not as accurate as it could be but close enough. The Total values are what ThortsMD provided me but he adjusted them slightly to deal with the trip not being reset till about a third of a mile in. So between that and the missing values it won't add up exactly.

    Trip Info for 85D from Visible Tesla

    This is links to the HTML exports of the trips between superchargers from VisibleTesla. The first and last trips to/from my home are omitted since this includes detailed mapping information. Yes I'm sure someone can figure out where I live anyway, please don't feel the need to prove this by being creepy. Distance is a little off here because VisibleTesla cut the trips in slightly different places. I don't have the same information for the S85 since it wasn't being monitored by VisibleTesla. There is also some gaps in the data due to the lack of cellular service along some of this route.

    Ellensburg to Ritzville
    Ritzville to Coeur d'Alene
    Coeur d'Alene to Ritzville
    Ritzville to Ellensburg

    Conclusions

    It's hard to make any conclusions. The 85D clearly used more energy but the following things might have contributed to that.

    • The 85D started the trip with 1,556 miles on the odometer. It's possible that various parts haven't had enough mileage to settle in. I believe the EPA tests were done with vehicles had 3,000 miles on the odometer.
    • Difference in the tires. Different brands of tires on top of the 85D tires being relatively new and the S85 tires nearing time to replace them.
    • The extra passenger in the 85D.
    • TACC being less efficient than straight up cruise/human driving. There are times when it does things less efficiently. However, the trip from Ritzville to Ellensburg with the 85D in the lead there were only two occasions where TACC slowed below the set 73 mph due to traffic. Looking at the data now however, I'll notice that the 85D was closer when it was following on TACC cruise.
    • The 85D itself could just be a tad less efficient when not used in range mode. We didn't do any range mode testing this time.

    When we were driving this today it seemed like we were a lot further off than sitting here now looking at the data. I suspect that the extra passenger really was the difference.

    I can probably publish a lot more data from my 85D, but without the corresponding data from the S85 I'm not sure how interesting it is. I suspect we'll do another drive sometime in the future compare further.
    �
  • Mar 7, 2015
    vvanders
    Any reason you didn't use range mode? My understandings is that's where the 85D is supposed to shine.
    �
  • Mar 7, 2015
    Andyw2100
    Yes, you definitely were not getting most of the benefits of torque sleep with range mode off. There have been several posts here that talk about that. Jerome Guillen has been the source for some, indicating that while there are some efficiency benefits from torque sleep with range mode off, there are significantly more with range mode on. I also posted something after speaking to a rep at the Tesla 800 number. I'll look for that, and edit this when I find it.

    Edit: Found it: P85D vs. P85 Efficiency Testing, Take 2 - Page 11 (Bold just added to highlight most relevant part)

    �
  • Mar 7, 2015
    Nevek
  • Mar 7, 2015
    dennis
    That's the second time Andy has been educated about NVH for the same post, with the same Wikipedia reference!

    P85D vs. P85 Efficiency Testing, Take 2 - Page 12
    �
  • Mar 7, 2015
    Andyw2100
    You make it sound like I didn't pay attention or something. I was only copying my post from the other thread above, for the relevant part. I didn't say, "Oh, and by the way, I'm still trying to figure out what those letters were." I did point out that it was an old post. I guess I could have added a note to say that later in the thread someone pointed out that the abbreviation was NVH. Oh well.
    �
  • Mar 8, 2015
    NOLA_Mike
    This part probably only applies to the P85D since it appears the 85D has the same motor front and back.
    �
  • Mar 8, 2015
    breser
    Sure. Because nobody feels compelled to use range mode unless they're really pushing the range of their vehicle in an S85. None of these legs were even close to pushing the range of the vehicle.
    �
  • Mar 8, 2015
    RLO
    @Breser:
    Thank you for doing this test, Very intresting!

    I have not seen any similar test anywhere else yet but I sure do hope to see more tests and may be results more in the favour of the D model when it comes to range. Theory from Tesla is one thing, results experienced by real users is another story.
    �
  • Mar 8, 2015
    mspohr
    I left range mode on since my initial hypermiling road trip in my 85D.
    Could someone explain the pros and cons of this setting?
    I haven't noticed any issues except power and regen are limited when battery is cold (but I can still accelerate way too fast).
    �
  • Mar 8, 2015
    breser
    Power and regen are limited when the battery are cold regardless. It seems that regen mode disables battery warming when heating the car from shore power. Doesn't as aggressively warm the battery. Limits the climate settings some. Does something with Dual motor cars and torque sleep. Frankly, Tesla has not been very informative about the advantages and disadvantages of it.
    �
  • Mar 8, 2015
    ModelS1079
    There is a significant difference in the heating level - fullness, temperature, fan speed - with Range Mode. Also w preheating via the phone app, it heats more slowly, less fully. That said, I leave it on Range Mode much of the time, and virtually all days when it's not crazy cold (e.g., -19 degrees a fews weeks ago), and virtually all of April through November, unless really hot and more AC desired.

    To be clear, the difference is only evident with extreme external temperatures.
    �
  • Mar 8, 2015
    richkae
    I think the difference you reported could easily be explained by the tires and the tires alone.

    If the experiment is done again I would recommend using the same brand of tires, with the same inflation pressure, tread depth and ideally the same age.
    �
  • Mar 8, 2015
    breser
    Changing tires is a bit far to go for a fairly casual comparison. We did try to control variables we could do reasonably but our real purpose was to head out to the new super charger in Coeur d'Alene and try it out.
    �
  • Mar 8, 2015
    Matias
    So what the result was?
    �
  • Mar 8, 2015
    jerry33
    Inconclusive. Too many different variable differences between the two test cars.
    �
  • Mar 8, 2015
    dennis
    I wasn't implying that you are a slow learner. I just thought it was funny that someone else referenced the same Wikipedia post. That's all.
    �
  • Mar 8, 2015
    mspohr
    I don't understand why it would limit battery heating on shore power since, well, it's shore power, not battery power.
    I agree that there needs to be better information about range mode.

    - - - Updated - - -

    I don't understand why it would limit battery heating on shore power since, well, it's shore power, not battery power.
    I agree that there needs to be better information about range mode.
    �
  • Mar 8, 2015
    Matias
    I just read tire test comparing brand new summer tires. The best vs the worst had 5% difference in energy consumption. So it is very difficult to get reliable results with different tires, if differences are small.

    - - - Updated - - -

    I would still like to hear the numbers.
    �
  • Mar 8, 2015
    breser
    I went ahead and added links to HTML output of the trips from VisibleTesla on the initial post.
    �
  • Mar 8, 2015
    stevezzzz
    Thanks to the OP for taking the time to do the comparison and report his results. I'd be really interested in seeing results using Range mode: that's where the D's supposed efficiency advantages come fully into play.
    �
  • Mar 8, 2015
    breser
    Range mode makes torque sleep more aggressive. There's a help text button on the range mode that says as much on Dual motor cars and Tesla has been telling people that. It's mentioned further up in the thread.
    �
  • Mar 8, 2015
    jgs
    Yeah, I just noticed #3. I'll have to go do some more reading, thanks. Actually I just deleted my mistaken post, but not fast enough I see. :)
    �
  • Mar 8, 2015
    Andyw2100
    You may be interested in this thread: Would you use battery heating if it were available?

    - - - Updated - - -

    I'm not criticizing you for not using range mode. But saying that one would only use it to gain range when they need it to "push the range limit" isn't really accurate. Anyone who wants to maximize the efficiency of the car, and thus use as little electricity as possible, might want to consider using range mode.
    �
  • Mar 8, 2015
    breser
    Sure but as far as we know on an S85 it does very little. Mostly (if not exclusively) climate control behavior modifications.

    We didn't need range mode anyway. The most risky leg was heading to Coeur d'Alene since nobody had confirmed (by way of actual use) that the super charger was working. But even then we had sufficient charge to return to Ritzville since we charged to 90% and Coeur d'Alene was only 91 miles away.

    I actually considered using range mode on the way back but decided that I didn't want to change too many variables since I also wanted to change who was leading to see if TACC behavior was involved.

    Like I said in my first post I figure we'll go somewhere else soon and use range mode there.
    �
  • Mar 8, 2015
    Andyw2100
    Right. I expect that's about all it does.

    I was just pointing out that there were reasons to use range mode in general (not on for your trip specifically) other than when worried about having enough range.
    �
  • Mar 8, 2015
    Danal
    Per other information from Tesla, most of the efficiency derived from Torque Sleep is because the motors are geared differently, not because they are different sizes. The gearing makes each motor "most" efficient in a different speed range. This should apply equally to P85D and 85D.

    This may or may not have been mentioned when Andyw2100 was talking to Tesla on the phone (original post quoted above).
    �
  • Mar 8, 2015
    jgs
    Let me quote myself (from An alternative to shifting in a Tesla... - Page 3)

    �
  • Mar 8, 2015
    breser
    This quote from the blog post seems on point

    Red text is my emphasis.

    I think this still leaves considerable room for debate about gearing. If they're identical how can one be more optimal than the other? He says the drive units are the same so wouldn't the gearing be the same?

    I think we still don't know enough in this area to be making definitive statements. And won't unless someone wants to do a tear down on 85D drive units. No I'm not volunteering my car.
    �
  • Mar 8, 2015
    jgs
    I think you just argued both sides there in just two short sentences, well done. I agree that closely parsing the red sentence lends a whiff of support to the "it's geared differently" theory, but it's only a whiff. (Just to continue the "how can one be more optimal than the other if they're identical" game a bit, in any given driving situation, RWD or FWD may be preferable in an otherwise-identical vehicle.)

    Agreed in every respect. Unless Tesla chooses to publish something about this, we will probably be waiting until someone totals an 85D. No rush.
    �
  • Mar 8, 2015
    Andyw2100
    I don't believe it was.

    I expect anyone could call and still get the same information read to them if anyone is interested.



    I agree.

    What I take from reading that statement is the following:

    In the P85D the fact that the front drive unit is smaller makes it more efficient to always keep that drive unit running if one drive unit is going to be sleeping. In the 85D, since the drive units are the same size, either unit might be the one that is running at any time, depending on which would be more efficient. If the only thing that could cause one to be more efficient than the other would be if they were geared differently, then I see this as supporting that theory.
    �
  • Mar 8, 2015
    billarnett
    It would be sufficient to measure the rotational speed of the motors. I suspect someone with a bit of EE knowledge and equipment might be able to do that without taking the car apart or at least by just removing some covers. Any takers?
    �
  • Mar 8, 2015
    Danal
    AC Induction motor RPM can be measured by measuring the waveform on any one of the 3 wires leading into the motor. Further, at these voltages/currents, a thin wire wrapped for a few turns around the motor input wire insulation is a sufficient sensor to then feed an oscilloscope for the measurement.

    I believe the wiring between the inverter and the motor is accessible... but I'm not absolutely certain. If it is, absolutely nothing needs to be opened or modified. Just accessed.


    Yes, I will try this; I cannot commit to when, as I will have to take the frunk apart to access the front motor wiring, and ??? apart to access the rear motor wiring.

    Danal

    - - - Updated - - -

    Question: Do we accept that the rear gear ratio is 9.73:1 on a "previous to D" Model S? There seem to be several credible sources for this. As in, people who have taken the car apart.

    Second Question: Do we believe the D rear motor gear ratio is the same as the non-D rear? I ask because I believe accessing the front motor is going to be MUCH easier than the rear, and I'd be much more inclined to at least try the front motor if we all agree to compare to 9.73. At least to start with... :)

    Danal
    �
  • Mar 8, 2015
    NielsHP
    Monitoring the frequencies (and currents) of the front and back inverters while driving could shed some light on this (if two identical motors are differently geared, the would very likely be driven with different frequencies).
    Also, it would for many reasons be a rather interesting data set.

    AFAICFO, using a non intrusive makeshift current transformer setup on one of the inverter wires (say, something involving a small copper coil and a soft iron structure), a USB sampling device, and a laptop would suffice.

    b.r.,
    Niels

    - - - Updated - - -

    Come to think of whether equivalent info is already present somewhere in the logs ?
    �
  • Mar 9, 2015
    breser
    When ThortsMD showed up I thought I had an additional advantage in the tires I had because of this:

    I'm not entirely sure which Goodyear tires he has. I do believe they were not the original tires on the car so they may not be the same tires that Tesla is talking about in quote above. During the drive ThortsMD said he thought the Michelin's might be stickier and get less range. I believe that my tires may not have had enough mileage to reduce the initial new tire efficiency loss. I've noticed my energy usage coming down like I remember was happening with my S85. Seems like around 2000 miles might be some sort of magic range where the tires are finally worn in.

    But I agree that tire differences are a significant difference in the test.

    - - - Updated - - -

    I think a better way of viewing it is the difference likely falls into the range of what can be accounted for the differences in the test conditions between the cars. 6% is easily accounted for between tires and the extra passenger. So we can actually draw a conclusion. That the 85D isn't likely to be significantly worse than an S85. This is still a valuable result for people trying to make a decision between and S85 and 85D.
    �
  • Mar 9, 2015
    jgs
    Unfortunately I can't see why we should make this assumption. The rear drive motor is different between D and non-D, so I don't see any compelling reason to assume the reduction gear mightn't also be different.
    �
  • Mar 9, 2015
    3mp_kwh
    I don't think its tires. Why would we expect dual motor to be more efficient, "S against S", vs. "P85 against P85D"? Torque sleep isn't mechanical. The two motors are either kept in the drive-line, or they are clutched out. They are either providing power, or they are idle/stopped, or idle/spinning. The latter makes the D more efficient when you don't vary that rotational speed (because of gearing), but to me it makes the relevant question:

    At what deviation from a dead speed does the "D" become less efficient?

    At your chosen drive cycle, it looks like "D" cost you 15-20 watt-hour/mi. I agree that around town efficiency isn't as important as "range when you need it", but believe we're headed to a point where dual-motor is simply regarded as less efficient, in daily use. No?

    If you think it is the tires, swap them and try again. Thanks for doing this.
    �
  • Mar 9, 2015
    richkae
    The tires are the only thing different on the 2 cars with known data about efficiency. The Michelin Primacy tires are low rolling resistance tires designed to improve efficiency - which is why Tesla offered them as an upgrade from the Goodyears.

    There are too many variables at play here for this data to provide even a hint of any difference between the S and the D. There may be a difference, but the original data has almost no value.
    In fact the title of this thread is ridiculously misleading.
    �
  • Mar 9, 2015
    breser
    Because the window stickers and Tesla says they should be. I'm assuming you meant "S against D". I'm going to ignore the P85 against P85D discussion since that's offtopic here and is being covered elsewhere and ultimately it just muddles up this discussion.

    Per Tesla's own information the 85D should be more efficient between 40 and 85 mph. Based on the direction of the lines on the graph it doesn't look like under 40 it becomes less efficient, but even if it does it's not relevant to most people because range is mostly important to highway driving that's almost certainly in the graphed range.

    Including the graph from the blog to illustrate this point.

    driving-range-for-the-model-s-family-chart2.png

    Based on one test? With a relatively low mileage vehicle. Without using range mode, that we knows changes how torque sleep behaves. I think it's far too early to jump to such conclusions.

    I'm certainly not going to spend money on tires just for this experiment. If someone else with Michelin Primacy tires with an S85 wants to do another test I'm happy to do it with them. But we know that tires are less efficient when new. Jerome told someone as much when the P85D's were new and the economy test procedure requires wear on the cars for the same reason. Comparing efficiencies overall the D was 6% less efficient. Considering the extra cost of an additional passenger and tires, I don't think we can assume that D is worse.

    - - - Updated - - -

    Say what? What's misleading about the title? I say it's a real world comparison. Guess what real world comparisons have differences that are hard to control for. If I said it was a well controlled laboratory comparison then I'd agree it was misleading. But I'm awfully offended by the characterization that the title is misleading.

    - - - Updated - - -

    I almost didn't reply to this but I'm having a real hard time believing this first paragraph is posted with the second one in this post. There clearly is at least one other significant difference, an extra passenger.

    You then go on to say there are too many variables. How can there only be one unaccounted for variable but then there are too many.

    Yes I get it the test isn't a perfect one. You're all free to go do a better test and post it.
    �
  • Mar 9, 2015
    Andyw2100
    I think it's both interesting and sad that when a guy like breser (or wk057) goes out of his way to try to post data for something like the above he's likely to get criticized for the test not being perfectly controlled.

    Switch tires and do it again? Are you kidding?

    In this case, breser just wanted to make a trip to a new supercharger. But instead of just hopping in his car and doing it on his own, he took the time to try to find someone on TMC with a car to compare efficiency results against. Then the two of them took the time to try to control for all the variables they reasonably could control for, record as much data as they could reasonably record, and then breser took the time to write it all up. And while many people are appropriately appreciative some are being, in my opinion, ridiculously critical.

    This may seem like a trivial issue, but I don't think it is. Because it's not just about this thread. In my mind, this is about what happens the next time someone is thinking about starting a thread like breser's. Does it get started, adding to the knowledge base for all of us, or does the person who might have started it think, "Why bother? I don't need the aggravation."

    I'd urge everyone to think carefully about what they're saying when they comment in these kinds of threads.
    �
  • Mar 9, 2015
    breser
    In fairness I said something about wanting to do the test and also wanting to do a road trip to the Coeur d'Alene super charger in two different threads and ThortsMD put the two together and sent me a PM. That PM was a critical part of the whole thing since I'm not sure when/if I would have made it out to Coeur d'Alene and I hadn't bothered to post something in the Northwest forum looking for someone to do the test for. So who knows when this would have been done if ThortsMD hadn't taken the time to contact me.

    Unrelated to Andyw2100's post I find the discussion of figuring out the gearing without taking the car apart fascinating. It's far beyond my expertise. I'm a software guy.
    �
  • Mar 9, 2015
    dirkhh
    I'm torn. I cannot help but think critically when I see data collection. Data are a wonderful thing and they are so easily misinterpreted... so I usually appreciate when people are asking critical questions or are criticizing overly broad interpretations.
    But yes, challenge the interpretation, challenge the assumptions, but don't challenge the volunteer work that is being done, don't make people feel unappreciated for their effort. Because even if the results aren't statistically relevant or sufficiently comparable, they still help us learn more about the cars, things that Tesla isn't telling us.
    So I think the answer is both. Be respectful and grateful to the people who are volunteering to collect the data, but don't overreach trying to interpret the data beyond what they really show.
    �
  • Mar 9, 2015
    breser
    The thing is the critical people aren't even challenging overly broad interpretations. For all practical purposes I said in my OP that I couldn't draw a conclusion. I later stepped that back a bit to say that I did think it was reasonable to say that the 85D isn't significantly worse than an S85. But nobody has really attacked those conclusions. They've attacked the methodology, most often the tire differences. I know the tire differences aren't ideal to the test, I said as much in my original post.

    If people want to do better tests then by all means please do. I'll try to do better tests assuming I can get willing participants (sorry I don't have two cars like wk057 does so I can do my own tests whenever I want). For instance next time maybe we'll try to offset passenger/cargo weight with ballast weight. Maybe I'll find someone with Michelin Primacy tires that wants to do a test too. Maybe I'll find a whole lot more people that want to go for a drive and we can have more vehicles in more different modes all running side by side. Next time I'll probably draw up a form to track our results to make sure we're tracking all the same numbers. There are a lot of different ways to improve the tests. But I'm not particularly interested in spending money on tires or swapping tires with another owner. I doubt I'd find another owner that wanted to participate under those sorts of terms.

    If you want to make suggestions on how to improve the tests or want to participate in helping improve them then by all means speak up. But the hand wavy, change tires response is just an easy and lazy response to make. The first time it was made on the thread, it was one thing, but to see it pop up several times over and over again is really tiresome. It's almost like I spent a bunch of time doing the test and posting the results so people can glance over it and then throw out an obvious response.
    �
  • Mar 9, 2015
    NOLA_Mike
    I see what you did there.

    And I like it. LOL
    �
  • Mar 9, 2015
    richkae
    I apologize for calling it misleading. I do not intend to imply any fault on your part, your post completely described the test parameters.

    Again I apologize. I did not intend to criticize you, I was overzealous in attempting to dissuade others from drawing conclusions from insufficient data.

    The extra passenger is a difference, but not one that is easily quantifiable.
    Tire manufacturers do controlled rolling resistance tests and publish the specs.
    Those tests control tire pressure, age, wear, and wheel alignment of the vehicles, which are unknowns here.

    The discussion should be constructive in helping determine what, if any, conclusions can be drawn, and how to perform a more controlled test in the future, if someone else were so inclined.
    I regret that I did not do that.
    �
  • Mar 9, 2015
    breser
    Thanks for the apology, I really do appreciate it. Seeing your post I realize now that you're probably just trying to discourage people running around insisting that the 85D is less efficient than the S85 and that Tesla is lying about it and then pointing at my test. I agree, my test does not support such a conclusion.
    �
  • Mar 9, 2015
    dhanson865
    Please do provide a URL for rolling resistance tests by tire brand, type, size, etc.

    I've done lots of research on this in the past and have found the public data spotty at best.
    �
  • Mar 9, 2015
    ThortsMD
    Thank you, Andyw2100, for that. This attempt was something of a "back of the napkin" attempt to get additional data to chew on. The effort was certainly not submitted for anyone, especially the OP, to get choked on.

    It was a 14 hour drive for me, from Seattle. We had beautiful weather, met lots of nice folks interested in electric vehicles, and I had a lovely day with Breser and his fianc� (thanks for the Model S cookies!). We are a community of passionate like-minded folks, by and large. Share the excitement. Drop the dour.

    �
  • Mar 10, 2015
    Matias
    I agree. Lets not shoot the messenger.

    - - - Updated - - -

    Car magazines do those tests. For instance Finnish Tekniikan Maailma just did profound summer tire comparison, which included rolling resistance measurements. But of course it is behind pay wall. Those tests are expensive to do correctly, I don't think anyone will publish results for free.
    �
  • Mar 10, 2015
    3mp_kwh
    Tesla jack pads are really easy to work with. A tire swap is what I meant. That would be really simple to do. Again, not looking to be ungrateful, but these "5%" efficiency changes from rolling resistance really need to be controlled out. You have consistent, point to point data, showing a watt-hour lag, in the "S-D" vs. "S". Others claim it could be the tires, and not only would it show up if you swapped. It would double. Taking 8 wheels off has to be one of the easiest non-events in how this data could be improved. No pressure :cool:

    I'm with the wrong crowd, if you guys don't have sockets, electric drills and at least a couple wrenches. I'll grant that the 21mm isn't the most common socket. Six, not twelve point, if you can.
    �
  • Mar 10, 2015
    NielsHP
    Following the thought of actually measuring motor currents and frequencies:
    Can any of you having access to an actual 85D (mine is still 2 month away) tell, how difficult (and dangerous) it will be to gain access (magnetic) to one of the main wires from inverter to motor, front and back ?

    aTdHvAaNnKcSe,
    Niels HP
    �
  • Mar 10, 2015
    Andyw2100
    No problem!

    And sorry I had not initially given you the credit for having sought out breser. (He later corrected that for me.) In my haste to post, I didn't go back and check the history of the thing.
    �
  • Mar 10, 2015
    Lloyd
    I had a ranger out yesterday. While upgrading my firmware to 6.1 xxx.179. He stated that most of the tweaks in this revision were for the D models to improve efficiency, and that I with a P+ would only see minor bug fixes.
    �
  • Mar 10, 2015
    breser
    I still think you're going to be hard pressed to find volunteers for that. I don't think even wk057 has done that in his P85 vs P85D comparisons despite owning both of the vehicles. You really think that relative strangers are going to want to swap wheels/tires for a test? If someone wants to do it I'd applaud their effort, but it's going far beyond my intentions of testing.

    - - - Updated - - -

    I didn't mention it but my car in the posted test had .179 on it.
    �
  • Mar 11, 2015
    tcampos
    This is an interesting thread and breser I thank you for posting the data. I'm a P85D owner and this whole thread takes me back 3 months when we were all trying to figure out why our P85Ds were getting such horrible range compared to P85s or S85s.

    I'm disappointed by the results posted here, and unfortunately not surprised. I'm disappointed because whether or not the methodology here was fully accurate, it clearly didn't show any improvement of the 85D over the 85 despite Tesla marketing the 85D as the most efficient vehicle in its fleet. I'm not surprised because when it comes to range, I find that Tesla's claims to be way less than trustworthy. I just don't believe them. Yes, some of that are variables, but compared to performance and safety, their track record here is pretty disappointing. With performance specs, the car seems to meet the claims. Safety wise, it seems to be better than claimed. But range wise, except for Cottonwood's recent post, I've not seen people be surprised by the range of the car (and neither have I).

    Lest this become a rant, let me make a more constructive statement - one of the things that I have learned from all of these range posts are what the controllable aspects of driving behavior are and the impact they have on range. So, for those who are taking the time to post and share this data, I thank you for your efforts
    �
  • Mar 11, 2015
    dirkhh
    This very much reflects my sentiment. I am sure that Tesla can demonstrate a controlled environment (flat, no wind, constant 65mph, something like that) where the D has better efficiency than the corresponding RWD Model S. In general driving conditions I would be very surprised if that was the case. The explanations offered by Tesla are hand waving and magical thinking. The car is heavier. More gears are turning, more energy is needed.
    And before the haters come crashing down on me... yada, yada, yada. The car is amazing, it could be far worse, yeah, we know all this. It's just that on some topics Tesla doesn't need the slimy dishonest sales people in the car dealerships - they are doing an excellent job challenging that spirit all by themselves. They finally cleaned up their act on displaying the price on the website. But the statements on how far you can go, how quickly you can charge and how much area is covered by superchargers continue to be just misleading at best and fraudulent at worst.
    �
  • Mar 11, 2015
    Andyw2100
    While I agree that Tesla may still be overstating their range claims some (I'll come back to this in a bit) I fear you both may be forgetting one pretty major point here: breser did this drive with range mode off. Tesla has said that most of the efficiency benefits of torque sleep require range mode to be on. So reaching the conclusions that you have, based in any part on this test, in my opinion doesn't make a lot of sense.

    The main reason I still believe Tesla is overstating the range claims is that I think they have not been forthcoming with the limitations of torque sleep. I think we are discovering that in cold temperatures torque sleep doesn't function at all. I think we're finding that above some relatively low power-draw, torque sleep doesn't function. So those of us living in cold climates won't see benefits from torque sleep at highway speed when it is cold, meaning that we won't have any extra range from torque sleep when it's cold, meaning we'll have far less range when we really need it.

    See this thread for details: Torque sleep not functioning properly on some cars? - Page 7
    �
  • Mar 11, 2015
    Coiled
    Slightly off topic, but it would be informative and relatively easy to compare range mode on and off in an 85D in mostly highway driving. Do the same loop back-to-back, with the only difference being range mode. Preferably 30+ miles of mostly flat highway. If that test has been done in an 85D, I missed it. It would be fascinating to see the results.

    I will do the test myself in a couple of months if nobody has by then.
    �
  • Mar 13, 2015
    breser
    I know this is not exactly a comparision to an S85 but I didn't really want to start a new thread for this.

    Did a 107.5 mile round trip today from my house out to Wallace Falls State Park in Washington. I did this route without range mode today and got roughly rated range. I hope to do the same trip tomorrow but weather conditions are not likely to be similar but I was just doing this route because I decided to go out there and because I wanted to compare our efficiency with what EVTripPlanner says. Cabin temperature was at 70�F the whole way. I figured 400 lbs of cargo between us and some things in the car.

    Location Time Temperature (�F) Rated Range (miles) Energy Used (kWh) Efficiency (Wh/mile) Distance
    Home (Leaving) 14:36 64 242 0 0 0
    Wallace Falls State Park (Arrival) 15:58 72 194 13.5 253 53.5
    Wallace Falls State Park (Departure) 17:27 73 193 13.5 253 53.5
    Home (Arrival) 18:58 65 135 29.4 274 107.5
    This trip is largely 2 lane highway that speeds up to 55 mph for some significant hunks but slows down as low as 25 mph through towns. Meaning it's much closer to what the EPA test cycles look like than my trip to Coeur d'Alene last weekend because I'm not going nearly as fast.

    Average Speed from Home to Wallace Falls was 39 mph, Speed multiplier of 0.925 on EVTripPlanner Equals this. Average temperature on this trip was 68. Trip to Wallace Falls is a drop in elevation of 351 feet (per EVTripPlanner).

    Average Speed from Wallace Falls to Home was 38 mph, Speed multiplier of 0.95 on EVTripPlanner Equals this. Average temperature on this trip was 69. Trip from Wallace Falls is a gain in elevation of 289 feet (per EVTripPlanner).

    The following is a comparison to EVTripPlanner
    Results from Distance Driving Time Energy Used (kWh) Energy Used (RM) Efficiency (Wh/mile)
    Actual to Wallace Falls 53.5 1:34 13.5 48 253
    EVTripPlanner (85D 19" tires) 52.8 1:22 10.8 36 205
    EVTripPlanner (85 S/P 19" tires) 52.8 1:22 11.5 38 218
    Actual from Wallace Falls 54 1:25 15.9 58 294
    EVTripPlanner (85D 19" tires) 51.7 1:22 11.6 39 225
    EVTripPlanner (85 S/P 19" tires) 51.7 1:22 12.2 41 237
    Fair warning that EVTripPlanner for the 85D is still in beta and the results may change. Given that I got roughly rated range and EVTripPlanner was saying I should get more I think it's safe to say that EVTripPlanner is probably presuming range mode.

    Something else I forgot to mention so I'm editing it in is we beat Tesla's estimate in the energy app for trip both ways. I didn't think to write down what the estimate leaving was.
    �
  • Mar 13, 2015
    vvanders
    I manage to beat the trip meter every time (with range mode).

    I'd really like to do a comparison with range mode on but it seems to hard to replicate anything more than 2 cars side by side. Just today on a 25mi trip of 50% 60/70mph @ 67F I saw 330 wh/mi out and 270 back (301 avg total).

    I think factors like headwind and tempature can easily eliminate any range gains of the 85D.

    We're heading out on a 300mi roundtrip tomorrow and I'll try and take better notes.
    �
  • Mar 14, 2015
    breser
    Repeated the trip from yesterday today using range mode. It was colder and was raining lightly when we left but the rain didn't last long and most of the trip was still on dry roads. As you'll note we did a little worse on this trip with a little shorter distance this time. I took a route that matches what EVTripPlanner does so I didn't have to put an extra way point in there to trick it to go the way I wanted. So despite going a little less distance we used a tad more energy. I'm guessing most of that is the heating. Same 70�F cabin temperature the whole way and 400 lbs of carbo.


    Location Time Temperature (�F) Rated Range (miles) Battery % Trip Estimated Battery % Energy Used (kWh) Efficiency (Wh/mile) Distance
    Home (Leaving) 15:07 59 237 88 64 0 0 0
    Wallace Falls State Park (Arrival) 16:25 58 187 69
    		14.1 269 52.3
    Wallace Falls State Park (Departure) 18:07 56 186 69 44 14.1 269 52.3
    Home (Arrival) 19:35 51 129 48
    		29.9 288 103.7
    Average speed from Home to Wallace Falls was 40 mph, Speed multiplier of 0.975 on EVTripPlanner equals this. Average temperature on this trip was 59�F. Trip to Wallace Falls is a drop in elevation of 351 feet (per EVTripPlanner).

    Average speed from Wallace Falls to Home was 35 mph, Speed multiplier of 0.85 on EVTripPlanner equals this. Average temperature on this trip was 54�F. Trip from Wallace Falls is a gain in elevation of 289 feet (per EVTripPlanner).

    Comparison against EVTripPlanner:
    Results from Distance Driving Time Energy Used (kWh) Energy Used (RM) Efficiency (Wh/mile)
    Actual to Wallace Falls 52.3 1:18 14.1 50 269
    EVTripPlanner (85D 19" tires) 50.6 1:16 11.2 37 221
    EVTripPlanner (85 S/P 19" tires) 50.6 1:16 11.8 39 233
    Actual from Wallace Falls 51.4 1:28 15.8 57 307
    EVTripPlanner (85D 19" tires) 50.5 1:28 12.3 41 244
    EVTripPlanner (85 S/P 19" tires) 50.5 1:28 13.0 43 256
    Comparison of deltas between trips and EVTripPlanner
    Delta between Distance Driving Time Energy Used (kWh) Energy Used (RM) Efficiency (Wh/mile)
    Actual to Wallace Falls (No Range Mode) EVTripPlanner (85D 19" tires) 101% 115% 125% 133% 123%
    Actual to Wallace Falls (No Range Mode) EvTripPlanner (85 S/P 19" tires) 101% 115% 117% 126% 116%
    Actual to Wallance Falls (Range Mode) EVTripPlanner (85D 19" tires) 103% 102% 126% 135% 122%
    Actual to Wallace Falls (Range Mode) EVTripPlanner (85 S/P 19" tires) 103% 102% 119% 135% 115%
    Actual from Wallace Falls (No Range Mode) EVTripPlanner (85D 19" tires) 104% 103% 137% 149% 131%
    Actual from Wallace Falls (No Range Mode) EvTripPlanner (85 S/P 19" tires) 104% 103% 130% 141% 124%
    Actual from Wallance Falls (Range Mode) EVTripPlanner (85D 19" tires) 102% 100% 128% 139% 126%
    Actual from Wallace Falls (Range Mode) EVTripPlanner (85 S/P 19" tires) 102% 100% 122% 133% 120%
    From what I understand EVTripPlanner was usually within 10% for people with S85s. If that's the case then then 85D is still using more energy even in range mode than an S85 based on this testing.

    One note on the rated miles. They are taken with range mode off to be consistent regardless of how the driving was done.
    �
  • Mar 14, 2015
    Andyw2100
    I'm more interested in why your efficiency didn't improve with range mode on. Do you think the temperature difference was enough to completely overshadow any efficiency gains from torque sleep?

    Actually I just did some quick calculations from some of your numbers. You can do more if you like if you think I am mistaken, but it appears you actually -DID-- see an efficiency improvement from range mode.

    I only looked at the wh/mi numbers for your four legs--to and from each day-- and compared them to the EV Trip Planner numbers you provided for the 85D. And doing that, you were closer to EV Trip Planner's predictions today.

    Actual wh/miEV TP Estimate% above EV TP Estimate
    Friday

    25320518.97
    29422523.47



    Saturday

    26922117.84
    30724420.52
    I think using the % difference from EV Trip Planner as the equalizing metric we can all use to compare things works.

    Some of the P85D owners who are seeing major improvements after torque sleep are beating EV Trip Planner estimates by 8-12%. Well, I should say they were beating the Model S estimates by that amount. I haven't gathered any data since EV Trip Planner added the P85D as an option, so they may be beating those estimates by less.
    �
  • Mar 15, 2015
    Coiled
    Kudos @breser for collecting this data. I wonder if the speeds (35-40 mph) are too low to benefit very much from torque sleep.

    In Tesla's range chart, there's no real difference between the 85D and P85D at 40 mph, but both are supposed to be ~6% better than the 85. So far I have yet to see either D get better range than an 85 in any test, at any speed, regardless of range mode. That's pretty disappointing.
    �
  • Mar 15, 2015
    breser
    I think there was an efficiency gain with range mode. You can see that clearly on the last chart.


    The whole last chart is pretty much every number from the actual to the EVTripPlanner estimate compared and represented as a percentage. Not sure why you decided to redo it. Unfortunately you also redid it wrong (you used the formula ((actual-estimate)/actual) when you needed ((actual-estimate)/estimate), you've actually calculated the improvement if the actual was the estimate and the estimate was the actual).

    - - - Updated - - -

    I'm not sure. Keep in mind the speeds are just the average speeds. There are significant hunks that are 50-55 and significant hunks that are 25. There are of course quite a few stops in there. So it could just be the extra weight from the front motor/other changes (~110 lbs over the weight of my S85) is just eating up the gains in the slow parts that are made in the fast.
    �
  • Mar 15, 2015
    Andyw2100
    I do see the efficiency improvement from range mode in the last chart. I have no idea what I was doing last night. I'll just blame it on being tired.
    �
  • Mar 15, 2015
    vvanders
    Did our ~300 mi roundtrip. Sadly rain on the first and last leg threw off the numbers.

    We did get a stretch with no rain, 55F outside, minimal climate(just front defrost when needed)

    16636368600_c499f45524_c.jpg

    Evtrip has same leg at 53.8kwh/286 wh/mi. The route was a lot of mixed 40/55/60(Centralia wa to poulsbo wa via US3).

    Also got this on the way back from home from Centralia
    16203822843_a57abc8b98_c.jpg

    Pretty sure the Tesla was acting more like a boat in the rain at 389 wh/m. I could see the energy tab change if I drove offset in the lane out of the ruts.

    Overall I haven't been able to see an noticeable improvement with range mode, I still plan to use it and do testing but it seems like the torque sleep efficiencies are well below weather based variations.
    �
  • Apr 11, 2015
    breser
    So I haven't been posting much partly because I've been busy and partly because I've been lazy about posting the data I have collected. I still need to spend some time to post some of the collected data but I can say that range mode is a significant improvement in the 85D.
    �
  • Apr 25, 2015
    breser
    So after nearly 7,000 miles I can same I'm pretty pleased. I'm getting pretty close to EPA rated (which would be 340 Wh/mile) on my rated. But i drove the car without range mode on for quite a while and the lifetime average is still creeping down. Range mode is a huge difference on the 85D. As you can see my 96.5 mile trip from the Burlington, WA supercharger today to home ended up being 306 Wh/mile. If I didn't live in a valley that I have to climb over the mountains to get in or out of I probably would do a lot better.

    IMG_20150425_193248.jpg

    I've been pretty sloppy about keeping records. I have some of my trips in VisibleTesla. But I haven't been tracking temperature and a lot of other things.

    I really need to find some time to do another decent road trip with a S85 owner and see how things compare now while controlling for weight.
    �
  • Apr 26, 2015
    Khatsalano
    S85D with 7,200 miles at 325 wH/mi lifetime. Range mode usually brings it down to 310 wh/Mi or less. I don't drive fast or drive hard, but 90% of my driving on highway so my lifetime average is higher than someone doing 50/50 highway/city driving.
    �
  • Apr 29, 2015
    Candleflame
    My car uses probably 10% more fuel with winter tires if it's not cold enough. I think this is quite relevant.
    �
  • Apr 29, 2015
    breser
    Neither vehicle had winter tires on and it wasn't cold enough for winter tires. The difference in tires was brand (S85 had the Goodyear Eagles and I had the Michelin Primacies) and wear level (S85 were nearly replacement, mine were new). I realize these are significant differences, if I hadn't realized that I wouldn't have pointed this out.

    If someone wants to do a comparison with less differences in the tire area, I'm not stopping them, but so far nobody else has done this.

    If you want a nearly perfect controlled test, use what Tesla is putting on the window stickers.
    �
  • May 10, 2015
    breser
    Well I'm about to set off to Paradise at Mount Rainier by way of Longmire. Trip will be ~227.2 round trip miles, EV Trip Planner says round trip that it'd be 208 rated miles. I have alternate charging plans, but I'm going to try to do this round trip without charging. I think it's going to be a stretch for the vehicle.
    �
  • May 10, 2015
    breser
    We made it on one charge. Did my first range charge, but I might have been able to do it without that (though I'd have very little buffer). We used range mode, though all rated mile numbers presented below are with it off. We had 3 adults. I drove at or below the speed limit. There were some areas I left it at 55 rather than going up to 60 and a hill that was right after a speed zone that I didn't accelerate up to highway speed to go up. I can't really calculate an average speed the way I usually do because we stopped and started several times. Trip is a little longer than planned because we made some side tracks (e.g. reflection lake) off the direct Paradise routing I'd planned.

    237.4 miles
    65.5 kWh
    276 Wh/mile

    17483787686_9046a2b68c_o.jpg

    Started with 100% charge, 268 rated miles.
    Arrived at Paradise with 42% charge, 114 rated miles (car estimated 41%).
    Ended with 13% charge, 35 rated miles (car estimated 9%).

    If you take the 35 rated miles and add it to the 237.4 miles we did you come up with 272.4 miles, exceeding the 270 EPA rated range.

    Watching the trip show the battery charge rising on our way down the mountain was highly entertaining.

    IMG_20150510_130454.jpg

    To say that I'm highly pleased with the range and efficiency of the 85D is putting it mildly. I'd thought about this trip with the S85 but didn't get comfortable enough with the car to try it. If the 85D has lost range for me from the S85 I don't think I would have ever tried this. I actually did this with my mom in the car.
    �
  • May 11, 2015
    Andyw2100
    Excellent post! Thanks!
    �
  • May 23, 2015
    breser
    Started planning to do another side by side comparison with an S85. We're thinking somewhere closer. I'm planning to come up with a form to keep track of data so we will be more consistent about what we're tracking this time. If I can convince everyone to step on a scale and can come up with some ballast weight we'll try to account for any differences in passengers.

    Just for fun here's my record lowest energy usage driving into work (for reference it's almost all highway only a few blocks either way off highway and 60-70 mph speed limits). Haven't really gotten close to doing that again (closest I've come is 300 Wh more).

    IMG_20150428_080956.jpg
    �
  • Jun 12, 2015
    breser
    ThortsMD and I are traveling to Pendleton, OR tomorrow. This time we're going to do a better job keeping track of data!

    IMG_20150612_215033.jpg
    �
  • Jun 13, 2015
    Matias
    Great!
    �
  • Jun 13, 2015
    spottyq
    Thanks Breser for taking the time to do these comparisons !

    Looking forward to your results.
    �
  • Jun 13, 2015
    Andyw2100
    So where are you stopping for the wheel swap? :)
    �
  • Jun 13, 2015
    breser
    Haha. Actually didn't need to do that to get some interesting results. I need to write everything up but here's a spoiler. The 85D did better this time.
    �
  • Jun 13, 2015
    Andyw2100
    I'm going to go out on a limb and guess that it was because you used range mode this time. Looking forward to the write up!
    �
  • Jun 14, 2015
    spottyq
    Nah, that would be an obvious question that someone would surely ask. I'm sure he did something more subtle. Say, opening all the windows and the pano roof on the 85. Or he conveniently 'forgot' he had 4 bikes wrapped in a thick blanket on the roof of one car.
    �
  • Jun 14, 2015
    breser
    At previously mentioned we made the trek out to the Pendleton, OR supercharger from my house in North Bend, WA and back with an S85 and an 85D. This post constitutes the writeup of that trip.

    Real World Test

    Before I get into the details I want to point out that this comparison is a real world test. It is not a laboratory experiment. We have not carefully controlled every difference. The 85D had two passengers compared to one in the S85 (and no despite joking about this above I did not get out a scale and control the vehicle passenger and cargo weights). Tires were of course still different. If the only comment you have is to suggest we should have swapped wheels/tires or gone to much greater effort to control the differences, don't waste your time posting. Instead go out and execute your own test with your own time and $200k worth of vehicles that meets the criteria you desire.

    The Vehicles

    S85 constructed in February 2013. Goodyear Eagle Tires with about 4k miles on them. Software version 6.2 (2.4.239).
    85D constructed in February 2015. Michelin Primacy Tires, the original tires the vehicle was sold with. Software version 6.2 (2.4.236).

    Both vehicles have a Pano roof. The standard 19" wheels.

    The S85 has an A pack and charges slower at the supercharger.

    Test Procedure

    In general we drove the vehicles back to back. With the 85D leading to Pendleton and the S85 leading on the return. There were of course instances where we got slightly separated in traffic. The vehicles were driven in range mode with roughly the same setting configuration. Climate set to 70�F (most of the time). ThortsMD mentioned lowering the temperature in his car at some point, but I don't know the exact details of which legs and how much he lowered it. We made no attempt to try and sync battery state of charge because of the differences in charging speeds. We spent around 5-10 minutes waiting for the S85 to reach a state of charge we were comfortable leaving with (due to the A pack). We ran around 3-4 miles per hour above the speed limit in most places.

    The Route

    We followed I-90 East to Ellensburg, WA where we supercharged and then followed I-90 east to I-82 to SR-22 (State Route) and then SR-221 and then SR-14 and finally back on I-82 to I-84 East to end up at the supercharger in Pendleton, OR. This is a shorter route than the one suggested by the car (following I-82 straight to I-84) and saves about 15 miles and 8 minutes of driving time. This accounts for a fairly significant difference in the estimated state of charge vs what we did (i.e. you can't really draw any conclusions about the estimate the trip planner gave).

    The Data


    S85


    		SLC* SLC* SLC* RR** RR** TP*** TP***
    Location Time �F Odometer Miles kWh Wh/mile Range Mode No Range Mode Battery % Estimate %
    Leaving breser's house 7:15 55 27,889 35.6 12.1 340 192 190 76 39
    Arriving Ellensburg, WA 8:23 59 27,966 112.7 37.2 330 103 101 41 N/A
    Leaving Ellensburg, WA 9:17 67 27,966 0 0 0 230 229 92 11
    Arriving Pendleton, OR
    		74 28,141 175.2 52.8 301 44 43 17 N/A
    Leaving Pendleton, OR 13:15 74 28,141 0 0 0 243 240 96 21
    Arriving Ellensburg, WA 15:49 78 28,316
    		 174.1 56.0 322 44 43 17 N/A
    Leaving Ellensburg, WA 16:28 82 28,316
    		 0 0 0 173 171 69 25
    Arriving breser's house 17:33 74 28,392 76.9 24.9 324 85 83 33 N/A
    85D


    		SLC* SLC* SLC* RR** RR** TP*** TP***
    Location Time �F Odometer Miles kWh Wh/mile Range Mode No Range Mode Battery % Estimate %
    Leaving breser's house 7:12 85/53**** 111,365 0 0 0 243 240 90 56
    Arriving Ellensburg, WA 8:23 58 11,443 77.4 26.2 339 147 145 54 N/A
    Leaving Ellensburg, WA 9:15 68 11,443 0 0 0 243 240 90 11, 12, 13�
    Arriving Pendleton, OR 11:56 73 11,619 175.8 54.2 308 45 43 16 N/A
    Leaving Pendleton, OR 13:13 76 11,619 0 0 0 253 250 94 20
    Arriving Ellensburg, WA 15:49 79 11,793 174.7 54.0 309 55 53 20 N/A
    Leaving Ellensburg, WA 16:25 82 11,793 0 0 0 205 203 76 46
    Arriving breser's house 17:33 75 11,871 77.2 23.9 310 118 117 43 N/A
    Leg Comparisons

    Leg S85 Miles 85D Miles S85 kWh 85D kWh S85 Wh/mile 85D Wh/mile
    breser's home -> Ellensburg, WA 77.1� 77.4 25.1� 26.2 324� 339
    Ellensburg, WA -> Pendleton, OR 175.2 175.8 52.8 54.2 301 308
    Pendleton, OR -> Ellensburg, WA 174.1 174.7 56.0 54.0 322 309
    Ellensburg, WA -> breser's home 76.9 77.2 24.9 23.9 324 310
    Overall 503.3 505.1 158.8 158.3 316
    		 313
    Overall the 85D used less energy on a total kWh and Wh/mile basis. On the way to Pendleton the S85 used less energy. On the way from Pendle the 85D used less energy. The trailing car always ended up using less energy on the specific legs.

    Conclusions

    I don't think these results are clear enough to say that the 85D is the clear winner. But I do think it means that it's plausable that it's slightly better.

    The 85D had an extra passenger and the S85 had a lower climate control setting, which I tend to think probably offset each other. On the Ellensburg, WA to Pendleton, OR leg it wasn't that far behind the S85 on energy usage even though it was the lead car.

    It's interesting to note that the 85D always ended up traveling more distance. Not a lot but it still did. This might be pushing the Wh/mile numbers down for the 85D. But it still managed to win the kWh on the return trip and the overal.

    You can debate about the tires since the Michelin's are supposed to be slightly more efficient. You can also debate about the mileage on the tires and if this put the S85 at a disadvantage (just as the 85D was at a disadvantage in the first test), but based on these results I don't think the problem on the first round was the newness of the 85D tires.

    Rather I think the first trip to Coeur d'Alene really does come down to just not using range mode. Range mode doesn't seem to make much difference in my experience with the RWD vehicles, but it makes a world of difference with the AWD vehicles.

    But while the 85D was slightly better it really wasn't that huge of a difference. Certainly not enough that I would think it should matter for a purchasing difference. The open question of course is if the extra passenger hid enough of a difference that it should still show in the rated range and EPA number. Or if the reason the rated range and EPA numbers are showing better is the issues with the odometer on the 85D (see other threads about that) and that the vehicles were actually much closer.

    Now don't get me wrong. Even making an AWD car having roughly the same range and efficiency of a RWD car is a significant accomplishment. I think Elon's comment that they improved the car in every way was fair (leaving aside the disputes over if he meant both the P85D and 85D or just the 85D).


    * SLC = Since Last Charge
    ** RR = Rated Range
    *** TP = Trip Planner
    **** Charging had just finished and the car's temperature read high. By the time we reached the interstate it had a lower temperature.
    � It started at 11% and then changed to 12% and then to 13% while I was just sitting there waiting to pull out and wasn't even moving.
    � Calculated after removing the Since Last Charge recorded when leaving breser's home.
    �
  • Jun 14, 2015
    Andyw2100
    Thanks for taking the time to do the follow-up test, and for posting such detailed data.

    You don't really mean that it traveled more distance, right, but rather that it reported a greater distance traveled for what was almost certainly essentially the same distance traveled.

    You are familiar with the controversy over the fact that the Ds over-state distance traveled in a way that earlier Model Ss did not, right? Edit: Just realized when I went back and read more carefully that you linked to this thread yourself above. Silly me. (I had read quickly the first time, anxious to get this post written!)

    Do P85Ds and S85Ds have inaccurate odometers that overstate distance traveled?

    It would be very interesting, for the purposes of the discussion going on in the thread above, to see what something like Mapquest or Google Maps gives as the actual distance for the legs in question, so that we could see how close the S85's odometer is to reality.
    �
  • Jun 15, 2015
    breser
    I wasn't making a judgement.

    From my home to Ellensburg supercharger Google Maps lists 76.4 miles.
    Between Ellensburg and Pendleton superchargers Google Maps lists 175.0 miles (both directions are the same mileage).
    From the Ellensburg supercharger to my home Google Maps lists 76.3 miles.

    However, I don't really think you can count on the online map numbers being accurate enough to be useful in this case.

    The interesting bit in the data, which I didn't notice until after I posted this. Ellensburg <-> my house was a difference of exactly 0.3 miles and Ellensburg <-> Pendleton was exactly 0.6 miles. I find it hard to believe that it came out to that exact difference if there isn't some difference in how the cars are calculating distance traveled.

    All that said 3-4 tenths of a percent difference doesn't seem like it's a big deal. So I'm not overly concerned about it. Probably well within the expected error difference. Could just be a matter of the difference in age of tires.
    �
  • Jun 15, 2015
    Andyw2100
    Thanks for posting the mileages from Google Maps.

    I agree that there has to be something different about the way the cars are calculating mileage. That has been the contention of those of us discussing the odometer issue from the start.

    While I agree the difference is not a big deal, if it's just a question of correcting an error in a calculation being made in the Ds, I'd like to see Tesla correct it. Except for the leg from Pendleton to Ellensburg, the S85 was closer to the Google numbers on all legs. The fact that Google has the mileage being the same in both directions of that leg makes me wonder about the accuracy of it, or if somehow the precise route you both took just actually was shorter.

    And as you pointed out, the S85D recorded higher mileage than the S85 on all four legs, in a very consistent manner.

    While this isn't a big deal, it also shouldn't be a big deal to fix if it's just a calculation issue.
    �
  • Jun 15, 2015
    spottyq
    I knew it ! The test is unfair because a fully charged battery weights more than a empty one. By as much as 3,45�g. The test is flawed !

    All joking aside, thanks again for taking the time to do such a test, to collect and post that data, and to eliminate as many variables as possible. I probably wouldn't have the patience to do it like you did ! :D

    I completely agree with your conclusion.

    Sadly, I can't give you rep at the moment, but I'll try to remember to give you some as soon as I have more of it.
    �
  • Jun 15, 2015
    3mp_kwh
    More food for thought, from a quick visit to Tirerack, shows OE Eagle tires at 755 revs per mi, vs. the MXM4s at 751. I'd expect the cars to have fixed revolutions per mile settings, however this difference is opposite to what is observed. The Goodyear shod S85 should over-state, relative to the MXM4 85D by .5%, if I'm looking at it right.

    Thanks for the real world trial!
    �
  • Jun 15, 2015
    glhs272
    breser,

    Minor thought... It looks like you both left from your house. Did the S85 also leave from your house cold soaked or did ThortsMD drive to your place, top off then continue on? Just thinking that maybe the early on results were higher for your S85D because it still had to warm up, where the S85 didn't.
    �
  • Jun 15, 2015
    Andyw2100
    If the above is actually a factor, it would explain why the D overstatement relative to the S was less than the .8% number that others had computed previously. The S, on non-OEM tires, was also overestimating the mileage some.
    �
  • Jun 15, 2015
    ThortsMD
    I drove from my house in Seattle to Breser's...about 25 miles. I did not top off at his house. It was in the mid 50's and my garage was warmer, so I was not cold soaked.
    �
  • Jun 15, 2015
    breser
    I also would not characterize my 85D as cold soaked. It had just finished charging to 90% very shortly before ThortsMD arrived (I started at 5:45 and we left around 7:15). To the degree that as noted in the data the outside temperature was showing as 85 when I pulled it out of the garage to leave, despite the outside temperature being 55.

    I'd be surprised if any battery heating was going on.
    �
  • Jun 21, 2015
    breser
    No comparison but had some fun going to Mt Rainier this afternoon. We actually got home with 19% left on the battery. 228.1 miles traveled, 60.1 kWh used for 264 Wh/mile.

    IMG_20150621_212207.jpg

    The hilarity that is the energy app after traveling down the mountain.

    IMG_20150621_200936.jpg
    �
    • Người đăng: vào lúc

    Không có nhận xét nào:

    Đăng nhận xét

    Đăng ký: Đăng Nhận xét (Atom)