Nov 30, 2015
AWDtsla 0.2 is just ~15% less than a Model S. Just losing the mirror and properly designed wheels will probably get half of that, forget about more advanced aerodynamic modeling. There are large losses in the small details that no one would notice change. Suspension parts? Less cooling?�
Dec 1, 2015
wdolson Unless they can get the laws changed, they won't be losing the mirrors. Every US state has their own mirror laws and the laws in every state will have to be changed before it will be practical to eliminate mirrors.
A summation of the laws in the US:
http://ecomodder.com/wiki/index.php/Mirror_Laws_by_State_%28U.S.%29
I'm sure most countries where Tesla wants to sell cars have similar laws.
The Model X prototype had cameras in place of the outside mirrors, but Tesla was unsuccessful in getting the laws changed.�
Dec 1, 2015
aronth5 Has Elon actually been quoted that the Cd will be under .2? All I have seen us that he is pushing the engineers hard to get there. Big difference.�
Dec 1, 2015
Rashomon In general, federal regulations in automotive supercede state laws. All that would be required is for the DOT to define a camera/display system as a mirror. Similarly, UN-ECE rules as set by the EU are the basis for vehicle regulation in much of the rest of the world. The VW group has already gotten an exemption for the XL1 to use cameras in place of mirrors, and both the recent Porsche and Audi prototypes were shown with cameras. These are strong signs that a regulatory change is coming for Europe. This still doesn't ensure the rules will change in time for the model 3, but I bet both design options are being included at this point.�
Dec 1, 2015
Max* It's my understanding that it's the exact opposite. The federal highway administration or the national highway and traffic safety administration set the minimum guidelines, and the states have the option to beef them up.�
Dec 1, 2015
ratsbew What if the mirrors automatically deploy based on GPS location and a database of state laws?�
Dec 1, 2015
wdolson Federal law trumps state law, but most of the rules on the federal level aren't laws, they are rules established by the DOT. State laws are crafted based on the rules, but unless state laws are in conflict with one another or dramatically deviate from the rules, the feds tend to stay out of state law. Every state law I looked at specified that cars needed mirrors to see at least 200 feet behind the car, but the wording is different in each state. What was consistent was the term "mirror" was used in all of them. I suppose Congress could pass a law to define a camera as a mirror for rear view purposes, but the current Congress is not very effective.
There are a number of articles out there on how it's probably going to be a while before the laws change and rear view cameras would be allowed in place of mirrors. There are a number of states out there that don't like Tesla and until the big 3 automakers start pushing for it, the states aren't going to lift a finger if it would help Tesla. The Big 3 don't want to advocate for anything that would help Tesla either, even if it would help them too.�
Dec 2, 2015
aronth5 One of the design considerations Tesla has is whether to use auto presenting door handles as an option or use more traditional door handles that are very aerodynamic.
I highly doubt the auto presenting door handles will be on the $35k entry model. So I wonder what the door handles will look like?
�
Dec 2, 2015
wdolson Hot spot door handles like the Model X without the auto open door mechanism.�
Dec 2, 2015
Colsla might come with tech package since it's the more 'advanced' technology?�
Dec 2, 2015
wdolson Why include cheaper technology in an upgrade?�
Dec 10, 2015
jscholl I think Colsla's idea might have been that the door handles will work like the front doors on the X, but the ability for the car to detect your presence and open the door for you, instead of responding to a press on the handle, would be in a tech package. At least, I think that's likely, though it does depend on how people react to auto-opening front doors on the X. There wouldn't be any hardware difference between auto-opening and not, as the ultrasonic sensors and the door motors would likely already be there, so I don't know if Tesla would make it standard to help say "wow, look how much more advanced our car is than other $35k cars" or if they would make it an upgrade so they can have higher margins.�
Dec 10, 2015
wdolson OK, I can grok that.�
Dec 10, 2015
Colsla my assumption being the tech that was introduced later would be considered more 'advanced' but I seee where my logic was flawed.�
Jan 18, 2016
coco81 I've just read that the new Hiunday Ioniq has 0,24 Cx... that's the same than Model S. Maybe it's not so crazy to achieve a 0,20 withhout being a weirdmobile and using wheel covers... (considering less cooling needs for the full EV and others improvements)�
Jan 18, 2016
WarpedOne Well, it is
All non-crazy ideas are used to get to ~0.24.
Then you can only use the crazy ones to get even lower.
The car will be smooth half-egg-shaped sooner or later.�
Jan 18, 2016
coco81 I mean if a traditional ICE car get 0.24... only removing almost all the cooling openings you should have even less Cx. Maybe 0.23... maybe lower. Of course 0.20 is an extreme result (if possible)�
Jan 18, 2016
LargeHamCollider Apparently the Bolt is at .312, so one can have both a high .cd and a weirdmobile!�
Jan 18, 2016
Yggdrasill The Bolt isn't a weirdmobile. Looks like most other hatchbacks.
If the Ioniq has 0.24, that's pretty good. I'm sure the 0.2 for the Model 3 is with side view cameras, flush door handles and similar improvements that the Ioniq doesn't have, so maybe the shape won't suffer too much.�
Jan 21, 2016
doubeld Am I the only one who doesn't give two hoots about the Cd, so long as the range is good? (Yes, I know one is affected by the other)
I can't wait for the day that battery tech is so cheap, that we don't have to have every car look alike "Just because they're aerodynamic".
Certain cars just look nice, but they might not be as slippery.
Really, people are so worried about side view mirrors or not having wheel covers, but in reality it takes what, maybe 2-5 miles off your range? Give me a bigger battery and call it even. Wheel covers are ugly, and they always will be. Hopefully I'll be dead before those catch on.�
Jan 21, 2016
coco81 Agree�
Jan 21, 2016
wdolson Drag makes a much bigger difference with EVs than it does for ICE. ICE engines are much less efficient overall, but the range over which they are most efficient is much wider than with EV which have a spike in efficiency around 25 mph and then efficiency drops quite sharply from air resistance as speed increases. Tesla had aero rims available for a short time when the Model S was new and the increase in range at freeway speeds was around 7%, I think some people have reported as much as 10%. Eliminating the mirrors would probably add about another 5% of the range.
These improvements would probably only be about 1/3 as effective with an ICE because of the inherent inefficiencies to begin with.
Electric motors have many advantages over ICE (better low end torque, instant torque, overall better efficiency, etc.), but it's a different technology with different energy curves. It's built into the Physics.�
Jan 22, 2016
Model 3 Yes yes! Give me a bigger battery! But, hmm... if I then remove the mirrors and put on wheel covers, I will get even more range! :biggrin:�
Jan 22, 2016
JRP3 All vehicles are affected the same way by aerodynamics, it has nothing to do with the efficiency of the drivetrain, which is of course much higher in EV's, across all speed ranges. The reason is simply that as of now EV's carry much less energy on board and refueling is much slower. If we get to 10 minute recharging and 350+ mile battery packs aero will be less important. Until then it just makes good sense to get "free" range by good design. Personally I think well done aerodynamics can look very good.�
Jan 22, 2016
wdolson I didn't explain it well. The laws of aerodynamics are the same for anything.
In engineering, you are always trading off one thing for another. With something like a car, the losses include heat, rolling resistance, aerodynamic sources, drive train losses, and some other factors. The positive factor that overcomes these losses is the power generated by the motor. All types of propulsion have a theoretical maximum efficiency. For an ICE, it varies a bit from engine to engine, but it's somewhere around 35%. That is you put one gallon (33 KWh) of gas through the engine and about 2/3 of it will be lost to heat and mechanical losses within the engine. This is before you try to do any work with the engine. Electric motors can have a theoretical efficiency over 90%.
ICE need to idle because they produce 0 torque at 0 RPM and it takes some time to spin up to a point where it can do any work. So the engine needs to idle when the car isn't moving. This, or course, is all wasted energy. ICE engines achieve their max efficiency at a certain RPM which is different for each engine. Transmissions are designed to keep the engine as close to that sweet zone as possible. One reason car makers are coming out with more and more speeds on transmissions and CVTs are on some cars. ICE cars also need a transmission to increase torque to the wheels at low speeds without overloading the engine and keep it from stalling.
Hybrids further try to eek more out of an engine by keeping the engine running at it's peak efficiency when it's running and to charge the battery if only part of the engine's output is needed for propulsion.
Most ICE cars have their transmission geared to be in the sweet zone of max efficiency somewhere around 60-70 mph. Again it will vary some from car to car, but it's true for most ICE. At those speeds, the aerodynamic drag is a greater factor than at lower speeds, but because the engine is running at it's most efficient mode, the overall efficiency is better at those speeds. If the car was geared to get max efficiency around 25 mph, the gas mileage would be even better if you really wanted to drive on the highway at 25 mph for long distances on a regular basis.
Electric motor cars have different efficiency curves. Most don't have transmissions because the sudden torque changes possible with an EV can rip apart a transmission, and while a transmission might help some, the benefit is nowhere near as great as you get with an ICE. Most EVs have peak efficiency around 25-30 mph. Most of the losses for an EV are rolling resistance and aerodynamic drag. Electric motors are not very efficient at very low speeds, but the efficiency flattens out at relatively low RPMs compared to ICE. This is a complex graph, but it shows the torque vs RPM vs efficiency for an electric motor
Even at 200-330 RPM an electric motor can by 75% efficient. Twice the theoretical maximum for an ICE.
At low speeds the car is overcoming rolling resistance. The coefficient of friction is different for a moving object than for a stationary one. If you have ever pushed a heavy object, it was really tough to get going, but much easier to keep moving once it broke free. That the difference between static and dynamic friction.
Anyway, once the car gets moving and the electric motor starts getting up into the 90% efficiency realm, you're moving about 25 mph. There is some aerodynamic drag, but not all that much yet, so the car's efficiency peaks around there. As you get going faster, the aerodynamic drag cuts into your efficiency more and more and there is very little you can do about it, unlike an ICE.
With Teslas people try to hypermile them by driving as close to 25 mph constantly for a full charge to get as much range as possible. Probably everybody here has come close to hypermiling an ICE. Simply fill up the tank and drive at low freeway speeds with cruise control on.
Anyway, that's the long winded answer. Yes aerodynamic drag follows the same laws of Physics on both types of vehicles, but it's a more important factor in an EV design than an ICE design. The same aerodynamic feature will increase gas mileage in an ICE, but what might only improve efficiency 1-2% in an ICE will improve things 5% or more in an EV.�
Jan 22, 2016
scaesare Yeah... even if impractical:
I think with the right focus, even wheel covers, could look good.�
Jan 22, 2016
JRP3 Actually a good hypermiler will not use CC because they anticipate upcoming road features and traffic, and they will not be driving at low freeway speeds since aerodynamics are still the main factor. They would probably use the lowest speed that allows them to be in overdrive without lugging the motor, maybe 40-50mph depending on the vehicle.�
Jan 22, 2016
jkk_ Agree with you completely.
Hear hear!�
Jan 22, 2016
AudubonB On first, second, and third thought, that's a fascinating comment, because it begs the following response:
Can you really think that the combination of tires and wheel wells to be good looking? At the very least, less ugly than wheel covers? Or are you inured to their looks only because that is what you're accustomed to?�
Jan 22, 2016
ecarfan Lo-Drag: Cd < 0.2
I do not find wheel covers to be inherently unattractive. I agree with @Audobon that we are all accustomed to seeing cars without them and may therefore prefer that look simply on the basis of familiarity.
It would be great it Tesla could come up with an aesthetically pleasing "aero" style wheel that was also functional in winter climates (would get clogged with snow and mud). That sounds like a difficult engineering and design challenge.
I would have no objections to rear wheel covers on the Model 3, or even on the S/X. Of course they would be detachable so those who don't like them could remove them.�
Jan 22, 2016
Twiglett the problem with saying "just give me a bigger battery" is that it costs more for every car.
Improving the aerodynamics doesn't always add cost to every car produced, but increases the range just the same.
so you could have a S85 with extra aerodynamic enhancements and get the same range as an S90, but the S85 costs you less.
For the Model3 that is important, especially at the low end of the range.�
Jan 22, 2016
AWDtsla You have a lot of words and data but the conclusion is still incorrect. Tesla's have a energy usage minima around 25-40 mph. ICE engines are so inefficient, the minima is slightly higher speed. However if you want to "hypermile" an ICE, you're not going 70 mph. You're probably going 45 mph, but totally dependent on a specific vehicle. At highway speeds aero drag dominates all energy use in either type of propulsion.�
Jan 22, 2016
jkk_ Out of curiosity, I have never seen / heard of a design that wouldn't get clogged with snow and mud, any idea if there is any such designs in existence?�
Jan 22, 2016
stopcrazypp From what I can find, the hypermile records for the Model S were achieved at ~25mph. Most hypermile records for ICE cars are done at ~45mph. Don't have the time, but I can probably find the efficiency differences (esp. the claim of the same aerodynamic change being half or less effective for an ICE vs an EV).�
Jan 22, 2016
AWDtsla It's not necessary, the claim is wrong. There are two competing curves of energy usage growing loss from drag and loss from everything else, together they form a minima that is the most efficient driving which is neither 0 nor max speed. It has nothing to do with being ICE or electric, except that they have different parameters. Like I said, ICE has a higher speed minima because it's so damn inefficient going slower doesn't help.�
Jan 22, 2016
wdolson If you look at the curves for this sample of ICE cars. The Prius has peak efficiency around 40 mph, but the Civic, 328i and Outback are all mostly flat from about 45 mph to 65 mph. Above 65 mph the efficiency starts to drop as the aerodynamic drive overcomes the motor running at it's most efficient setting.
�
Jan 22, 2016
JRP3 Contrary to the graph title those plots are not the same pattern, and something very odd is going on with the curves, especially the Honda which seems to show a 6-7 mpg improvement at 70mph compared to 60mph.�
Jan 22, 2016
doubeld It's a somewhat ignorant comment, and I knew eventually someone would give me some flak for it. Wheels break up the monotony of a steel/aluminum/plastic body. There's a reason why people will spend thousands of dollars on them. They let people customize the vehicle more than the manufacturer lets them. Plus, you can get light-weight, or cheap steelies for the winter or what have you.
Wheel wells are functional, at least for the steering wheels. They let the tire protrude outside of the body of the car to turn sharply without having the body of the car be as wide as the widest it is when it's turning. To diminish that would diminish handling. The amount of energy saved by having wheel covers is not worth the $$$ spent on a larger battery in my very own personal opinion. Hence my reason for bringing this thread back from a recent death.�
Jan 22, 2016
wdolson I noted that too, which is odd.
Here are curves for some other cars:
These curves have their variations too, but they have similar shapes. Some peak in the 45 mph range, some at higher speeds. A lot depends on how the car is geared.�
Jan 22, 2016
AudubonB Fair enough response (doubeld's #158, that is); the reason I'm jumping on it is, however, for a somewhat different purpose....but a reason that still falls under the "low Cd" aegis so I'll claim this is not diverging from the thread topic. As follows:
You write.
I've been thinking of this in recent weeks. Given the astonishing ability of automotive computers nowadays to gather information from all four tires and respond as appropriate, does anyone think that a front end that had a narrow wheelbase might become workable? That is, if a car had its front wheels brought in just enough so that at full turn, the tires still remained inside that which we're all calling wheel covers, could it still be a stable, safe, properly-handling vehicle?
The reason for such thoughts should be clear - this would be one path toward optimal front-end aerodynamics. I've had some thoughts as how to mitigate snow and muck build-up in wheel wells, too, but needn't discuss them here. All this is moot if such a vehicle's handling, stability and safety could not match its wide-tracking counterpart - to me the Cd gain would not outweigh those ultra-important criteria. But thanks for bringing it up!�
Jan 22, 2016
doubeld I'm no engineer, but I would suspect that anytime you narrow your contact points on the pavement you increase body roll which has an obvious impact on handling.�
Jan 23, 2016
JRP3 
http://www.deltawingracing.com/
�
Jan 23, 2016
1208 Maybe at the press of a button a tail could extend out the back.
�
Jan 23, 2016
JRP3 Like this: https://youtu.be/qaR20sGX9ik?t=2m56s�
Jan 23, 2016
ohmman I think AudubonB's discussion about wheels applies directly to an extremely aerodynamic shape as well. We're accustomed to seeing vehicles appear in a certain aesthetic. Over time, if designers can push our comfort zone ever so slightly, we can be normed toward a shape we might consider "odd" today. This happens all the time in style and art.�
Jan 23, 2016
jkk_ Fair enough and I can get behind that. However, one thing that troubles me is that I have gotten the impression (which can be wrong) that people are advocating for covered wheels / wheel wells / etc from the standpoint of "we can shave off 1% of drag and gain 2% of range" while at the same time forgetting that more likely than not, these solutions will cause significant concerns and issues in places where we get plenty of snow (including wet snow when it's around just above 0C degrees, which is very heavy and sticky).
And yes, I'm probably too cautious regarding this issue, but for me reliability is more important than the gains that might be achieved via this method. And in any case, all of this is just pure speculation anyway, Tesla has surely made their mind already and we will see "which side was right" soon
�
Jan 23, 2016
wdolson The aero wheels for the Model S that were only available for a short time increased range by about 7%. Completely covering the wheel well would improve range even more. However I agree with you on the practical aspects with getting packed with snow as well as other gunk collecting under there.�
Jan 23, 2016
JRP3 It would be much more than that.
Optional and removable, i.e., if you don't want them you don't have to have them.
I don't actually expect wheel covers on the 3.�
Jan 24, 2016
S3XY Sounds like the aero wheels are a good compromise between reduced cd and aesthetics. They just need to design ones that look good and make them standard rather than an option. Then they can include the added range in their EPA rating.�
Jan 24, 2016
Twiglett All of these sleek body shapes look the part.
But does anyone remember the Mythbusters episode where they proved the the best performance came from the dimpled "golf ball" indentations along the body.
They got an 11% efficiency boost just by adding all those dimples.
Thats will the ugly grill, no wheel pants etc etc
Kinda makes the piddling 5% from adding wheel covers looks silly�
Jan 24, 2016
JRP3 Of course all those dimples look great....�
Jan 24, 2016
physicsfita After seeing that episode, it made me wonder if something along the line of the riblets that are put on the hulls of race boats could be developed for cars (and could be made to not look awful). I'm guessing there must be some practical reason why not since we don't see anything like that on racing cars, and I would be amazed if some team out there hasn't given it a try.�
Jan 24, 2016
dgpcolorado Hmm... Does that mean that hail damaged cars get better mileage? That's an advantage I'd never have thought of!�
Jan 24, 2016
aronth5 For those that never saw the episode
�
Jan 31, 2016
David_Cary Aerodynamics will be good (hopefully). Style will eventually match function as it has to.
.2 will be normal within a decade I suspect. The best way to travel faster is with better aerodynamics. I want 100 mph as normal in a decade and doing that with a .3 Bolt is going to be silly�
Jan 31, 2016
aronth5 100 mph, where? I didn't know they were planning on building an autobahn in North Carolina!�
Feb 1, 2016
Touring Would be good selling point for tech interested costumers with cd<0.20. Would look more futuristic, and will be good for marketing, efficiency and performance.�
Feb 1, 2016
Gerasimental
Most racing cars are designed for high lift, not low drag. Drag coeff of an F1 car is around 1.0 (depending on set up). Would be pretty awesome if this was what he meant by 'won't look like other cars'.�
Feb 1, 2016
cokata Your example is of the worst case scenario (open wheel, open cockpit) car. LMP1 cars have much more DF than F1 and are ~0.45.
Anyway i would take a smaller battery with better aero (for the same range) everytime, because it will reduce the penalty of more spiritual driving, also better aero means better performance at higher speeds, something that the Model S is really lacking (not that it's an aero issue)�
Feb 1, 2016
1208 �
Feb 1, 2016
roblab Agreed. People already can't drive at 50, want to do 75 and 80. Doubling the speed increases impact damage four times.
Most people don't inspect their cars, don't know if their tires are under pressure, can't drive in rain or snow, don't turn on their headlights in fog. They drive and argue, drive and play with the tunes, drive and use the phone. And they think a beer or two, or a glass of wine at dinner is OK when eating out. And then they drive home.
The one thing I don't want is some doob driving disabled or unaware coming at me at a hundred miles an hour.
Why are we in such an everlasting hurry?�
Feb 1, 2016
ohmman To be fair, a decade will likely see us into the autonomous driving era. 100 mph may be in a dedicated freeway lane for autonomous cars only. Maybe.�
Feb 1, 2016
1208 No sane person would want to go 100mph in an autonomous car...
I'm all for it.�
Feb 1, 2016
ohmman Ever since I was a kid, I've imagined a sci-fi scene where thousands of vehicles are traveling at very high speed through a complex interweaving network of roads. The intersections don't have traffic lights, the vehicles just adjust their speeds by tiny amounts to anticipate and avoid the other vehicles crossing and merging into their paths. If I had CGI skills, I'd work on an animation of it, because I think it's a cool and terrifying concept.�
Feb 1, 2016
Quant
This is how airplanes and radar based flight control and navigation work in almost the entire 3D space ( due to military zones). The issue is doing in on a 2 D road or highways, with million times more vehicles, and 2D limiting highways using rubber tires and hydraulic braking that uses friction and encounters other complex forces . This makes the situation way more risky, mathematically speaking.�
Feb 2, 2016
David_Cary First of all - I think the amount of traffic deaths/injuries is a travesty. But autonomous driving is a game changer and the primary reason it should be pursued. If you don't feel that autonomous driving is safer than any rational discussion is over.
In 30 years we have gone from 55 to 80 at the high end with an every year decrease in fatalities per mile driven. Progress continuing and increasing in speed means 100 may be a decade away. And in my mind electrification and autonomy should increase the speed of speed increases.
Most experts think full autonomy is 5 years or so away. So majority of miles driven autonomously could in a decade. Most miles go on newer cars.
I have a son who just turned 6. My sincere hope is that 2010 is the birth year where you can no longer drive a car. So in a decade when autonomy is majority of miles driven, the driving age jumps to 21. Then 5 years later it is gone forever. I love to drive but it isn't worth the cost to society - ie I hate traffic and traffic related injury a lot more than I like to drive. Most parents would agree. Who hasn't known a life ended or changed forever from a car accident. Estimated cost $1 trillion a year in the US. Is driving that worth it? Maybe to car forum people but not society at large.
And hopefully it means I can get to the beach in 1.5 hours instead of 2.25.
4 times the force at double the speed. Sure physics. But no one hits a wall at freeway speeds. They also don't have head on collisions on the freeway.
"Why are we always in such a hurry?" - I have to poke a little here without meaning to be obnoxious. This forum is CA heavy for obvious reasons. In the East, we are in a hurry. We just are. Getting more out of life involves not sitting around. Car time is generally wasted time. It is why people multitask in cars. It is the future which is why autonomous driving is so important. The supercharger road trip discussions amuse me - a lot of West coasters telling us to slow down and smell the roses. Not going to happen.�
Feb 2, 2016
mkjayakumar I am worried in order to achieve a low CD they will make the car so low like a sports car, it just would make the ingress/egress so much more difficult..�
Feb 2, 2016
tga So in 15 years, we're going to revoke everyone's driver's license and cancel the registrations on all non-autonomous cars? Since no one will be able to drive all the old non-autonomous cars, the entire US fleet will be worthless? For many people, an auto is the biggest asset they have. We're going to obliterate what little net worth they have and destroy their trade in value, to buy a required autonomous car, that they can't afford anyway?
Not gonna happen, at least not in our lives...�
Feb 2, 2016
eisbock Lol.
We won't see fully autonomous driving in our lifetime and I'm only 25. We wouldn't be able to pass the law to enact autonomous driving in 5 years' time even if the technology was perfected. Not even close.�
Feb 2, 2016
ecarfan Lo-Drag: Cd < 0.2
You are pretty pessimistic for a 25 year old.
Google has had fully autonomous cars on the road for a few years now and they have been proven to be safer than conventional cars. They just aren't selling them...yet.
It seems clear to me that in less than 5 years, and maybe less than 3, fully autonomous cars will be available to buy and drive. The law will require that a licensed driver must be in the driver's seat at all times and ready to take over at any time, just like now with Tesla Autopilot. Except that a few years from now Tesla Autopilot will be able to drive the car from A to B without human intervention.
I hope you don't go through the rest of your life with such a negative outlook. Cheer up, the future isn't all bad. ;-)�
Feb 2, 2016
Kevin Harney A car is not really an asset. Well, ok if it is paid off it is an asset but it is still depreciating and not an investment. I guess technically you are right it's an asset. But if it is your biggest asset you have far more problems than autonomomous driving wrecking (pun intended) your balance sheet. And what teeny tiny percentage of the population has a car that is over 15 years old ?�
Feb 2, 2016
ohmman While I don't agree with registration and license revocations happening anytime soon, I do think the US fleet will rapidly become worthless. This will be a function of the technology and market forces and has nothing to do with us "obliterating" someone's net worth. The key is that buying autonomous cars isn't going to be how it works for most people, based on how most people see the field progressing. Most of the population will stop owning cars - you'll call them when you need them and they'll take you where you're going. The 20-22 hours a day when your car is not being used? That's a model that makes very little sense when vehicle sharing can happen without a driver.�
Feb 2, 2016
eisbock
If it was unclear (probably was), I was referring to laws that would mandate self-driving, effectively making it illegal to drive manually.
I'll admit, I am a pessimist, but I think that mostly stems from trying to be realistic! I'd sure love to be proven wrong though. After all, you're never disappointed when you're a pessimist!
I'll believe you if the Model 3 reveal goes well!�
Feb 2, 2016
tga Yeah, I'm rethinking that a bit. I suspect the number of people who pay cash for, or make large (like, >50%) down payments on cars, but don't own homes is probably pretty small. The real bottom of the economic ladder buys a clunker at usurious rates from the "buy here, pay here; $30/week" used car lots and have little or no equity in their vehicles. If they ever get close to paying it off, the car probably isn't worth anything by then anyway.
Over time, the non-autonomous fleet will age out, and be gradually replaced with autonomous vehicles. It'll be handled by natural market forces, not legislative action. You won't see government banning non-autonomous cars; it would be political suicide for any legislator. Most people won't get a driver's license because they won't need one, if 90% of the used fleet and 100% of the new fleet is autonomous.
For it to work, the shared cars have to be close enough to the users that they can summon a car with near 100% success with just a few minutes of waiting. Someone out in the sticks would have to schedule a trip to the grocery store 2 hours ahead of time to reserve a slot. Impromptu trips would be impossible. That model only works in cities and dense suburbs. I just don't see it making sense keeping stocks of shared cars in low density areas.
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Completely unnecessary. Once 99.9% of the cars on the road are autonomous, no one will care about the occasional person driving a non-autonomous classic from the 2010's. The few hundred accidents a year involving non-autonomous classics won't register on anyone's radar.�
Feb 2, 2016
ohmman Correct, this is the limitation, which is why I indicated "most people". Occupants of very rural areas will be unlikely to get rid of their traditional manual automobiles for a long time anyway.�
Feb 2, 2016
gregincal I don't think you are thinking in the proper scale. Sure people living in rural areas might still need to have their own car, but a tiny town of 2000 people could easily have a couple hundred autonomous cars waiting around (just like today they have several hundred cars). The model does not work just in cities and dense suburbs. As a matter of fact, I'd say anybody living anywhere where there are more than about 50-100 people within a 20 minute drive could use the model, which probably accounts for the vast majority of people. It's not like the cars need to return to some central dispatch when they are not being used, they just sit around near where the last driver left them, or use predictive algorithms to drive to near where people are likely to need them. This is when everybody has fully converted. Obviously it will start in cities and dense suburbs.�
Feb 2, 2016
Max* Google's fully autonomous cars still need intervention occasionally. So it's not really fully autonomous yet, which is why Google isn't selling them yet. Will they get there soon? I'm sure they will. Will it be in my lifetime? I'm sure it will.
Also, Level 4 autonomous cars will not be out in the wild ready to buy (with software) in 5 years. Level 3 (highway only), sure. And if the law requires that, then it's not a Level 3 car. A Level 3 autonomous car can have the driver take a nap, and the car is required to give enough notice of a situation that it can't handle to the driver (unlike Level 2, AP that we have now, which can yell "TAKE OVER IMMEDIATELY")
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Except that the other 2-4 hours are when the majority of people will need cars (for those with typical 9-5 schedules).
So while I agree, there is a future of shared cars in large cities, it's a very distant future to have shared cars in the boonies.
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Nevermind
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Except they need to charge. And 200 miles may seem like a lot in/near a city, out in the sticks, it might not be all that much if 3-4 people need to use the car back-to-back.�
Feb 2, 2016
gregincal That's a pretty easy infrastructure problem. Most roads have electricity, even out in the boonies.�
Feb 2, 2016
dgpcolorado Really? I drive a lot of roads that aren't near the grid. That's what it means to be out in the boondocks.
When it comes to driverless cars being able to handle difficult mountain roads and driving conditions I am skeptical. I suppose that GPS with one cm accuracy could manage to keep a car safely on a road and the onboard tech can see and avoid rocks and animals on the road. And snow, ice, potholes, washboard and the like. But I am not going to hold my breath waiting for this to happen.
Sure sounds like an urban sort of tech to me.�
Feb 2, 2016
AudubonB Indeed....�
Feb 2, 2016
gregincal I'm not talking about the roads you drive, I'm talking about where you live. You aren't going suddenly find yourself out in the middle of the wilderness and think, hey I need to go to the grocery store. And there is a huge amount in-between urban areas and remote mountain roads. Everybody (including me) has said that it won't be applicable everywhere, just for most people. By definition most people don't live way out in the boondocks (or they wouldn't be boondocks).�
Feb 2, 2016
AudubonB True (and here I'm guilty of keeping this thread waaaay off topic). But some of us boondockers do own Teslas...and we'd like to be able to persuade others to do the same.�
Feb 2, 2016
wdolson I expect autonomous cars will phase in slowly. There will be special lanes for autonomous only cars and maybe other incentives that encourage people to use them. As more and more of these cars become available, entire highways will got full autonomous. It will become necessary to buy an autonomous car in some areas if you want to get to work on time. For example if most of the freeways in the Los Angeles area were autonomous only, people who had non-autonomous cars could drive surface streets, but anyone who wanted to get anywhere at a decent rate would go autonomous.
There will be holdouts with older people who don't trust the technology and some young people who really like driving themselves. There will also be classic car lovers who restore old cars and take them to shows and such. Today we have cars on the road occasionally from as far back as the 1910s or 1920s. They aren't capable of the speeds of modern cars, nor do they have anything like modern safety features, but they are allowed on the roads too. Sometimes with limitations. There are a lot more classic cars from the 50s and 60s on the roads and some are daily drivers.
In the world of aircraft there are a fair number of classic aircraft from WW II and earlier flying. Many times these planes have limitations put on how they are operated, such as being limited to good visibility conditions only (no night flying and only in good weather). This is to limit the chances of these planes flying into a more modern plane which does have the current safety gear and/or ground obstructions. The world of aviation will probably be the model used as a template for incorporating self driving cars. The issues in aviation aren't all the same, but there are enough overlaps to be worth studying.
In any case, we're going to have to support non-autonomous cars in some way for at least 20-30 years. In places that salt the roads, cars fall apart fairly quickly, but in places where roads aren't salted (all of the western US and warmer regions), the body on a car can last virtually forever and the poorest people are driving the oldest cars for the most part. I saw a 1970s Camaro a couple of weeks ago. It's also not unusual to see 1970s pickup trucks and cars from the 80s around here. At this point, probably 80-90% of the cars on the road locally were built in the last 20 years, but I drive a Buick that's almost 24 years old and it's in pretty good shape.�
Feb 2, 2016
David_Cary See I don't buy that driving will be allowed. When autonomy is fully available, drivers will be a real drag. The LA freeway is the best example. The current average speed on freeways in the LA basin is probably 25 mph. With no drivers, it could be 60 mph. (WAG)
So the 10% holdouts will be overwhelmed by the 90% that don't want to waste their time in traffic.
The insurance industry will help of course. Autonomous car $150 a year. Driver $2000 a year. Interest on that new car seems very reasonable now doesn't it?
I suspect CARB will eventually help in CA. Higher registration costs for ICEs. Super high costs as cars get older.
Then there is the money equals power argument. The folks that drive 10 yo cars (with the exception of classic cars) have no money and no power. On average. Not always.
I still think the right way to do autonomy is to remove drivers. Makes autonomy much easier. Hard to accomplish for sure. But what does the AARP want? 20 yo drivers or mobility for the elderly?
Again politically tough. Easier to never give someone a license than take them away. Raise the age - I have 10 years.�
Feb 2, 2016
tga I assume you mean higher registration costs for non-autonomous. ICE != non-autonomous. You could build an autonomous car with either ICE or EV.�
Feb 2, 2016
wdolson There is a video out there that runs the numbers on how long it takes to just replace 50% of the cars on the road, they came up with 10 years just for 50%. The average age of new car buyers in the US is 49 years old because younger people don't have the money for new cars and buy used and the millennials are said to be the first generation in US history who will not make as much money as their parents. That means that unless something drastically changes in the US economy, the younger generations will be driving older cars longer than their parents did and that will slow down the introduction of autonomous only roads.
The poorest segments of the population unfortunately get screwed in the end, but there are a lot of working poor who can't take public transport for one reason or another and need to drive an old beater to work. If the roads convert to autonomous only too quickly a lot of places like Silicon Valley will find themselves trying to get by with no janitors, fast food workers, or other service workers. You can claim that a lot of those jobs in 10-20 years might be taken by machines, but that will just make life even worse for the poorest segment of the population and when the options for work get too severe for these people, it will likely lead to civil unrest.
The economic factors lean towards it taking more than 20 years rather than less.�
Feb 2, 2016
aronth5 Any chance we could get this thread back on topic?�
Feb 4, 2016
malcolm Here ya go...
http://www.atzonline.com/Aktuell/Interviews/35/147/A-Drag-Coefficient-of-0-2-Represents-the-Sound-Barrier.html�
Feb 5, 2016
David_Cary Interesting article - but full of plenty of conventional thinking.
Obviously an ICE has constraints that limit the aerodynamics that don't apply to Tesla. The article didn't mention mirrors at all which I thought was strange.
Look - the S is .24 and I would think .2 is approachable/reachable with better nose cone (ala X), no side mirrors, aerodynamic rims, and tighter seams. Perhaps wheel well covers - eventually this should happen�
Feb 5, 2016
wdolson Getting rid of the mirrors has a lot of legal hurdles and it's a drag factor car designers just have to live with until enough jurisdictions change their laws to make it possible. I don't think any country or any other jurisdiction has changed their laws on external mirrors yet.�
Feb 5, 2016
scaesare Interesting article... but this is why online articles/interviews need dates:
"The most extreme low-consumption concept car currently on the market has a cdA of 0.28 m2"
How long ago was that written?�
Feb 5, 2016
gregincal That's cdA, not cd. The XL1 has a cdA of .279, the Model S has a cdA of .576�
Feb 5, 2016
scaesare Understood. But I have no idea if he's talking current, or as of 5 yrs ago.�
Feb 5, 2016
gregincal Well, since the stats it gives as the current best matches the XL1 stats, which is definitely the current most extreme low consumption car and was released only two years ago I would say the article is fairly recent. (I do agree in general that I find it very frustrating on these sorts of articles to not know whether it's current or really old. All articles really should have a date.)�
Feb 5, 2016
CTemp222 Don't know if someone has said this but Tesla could make wheel covers that extend at highway speeds and contract when moving under 50mph.�
Feb 5, 2016
wdolson That would be an engineering nightmare, especially if the fenders have any curves in them. It would likely make the fenders very clunky looking to accommodate a panel sliding back into them. It would also require space be taken up by the actuator motors. If they did anything like that for the Model 3, it would not be available on the base model and would likely cost a couple of thousand at least.�
Feb 5, 2016
CTemp222 Well it sure would look better than permanent wheel covers imo. and they could probably fold up when contracted to save space.�
Feb 5, 2016
wdolson It probably wouldn't look better because of the design compromises needed to allow the covers to retract into the fenders. They have to store somewhere when not in use. Additionally, you would be designing a very complex mechanism that needs to operate in the part of a car most subject to collecting muck which would likely result in them jamming a lot.
The falcon wing door design was a major factor in the delays with the Model X. This idea is possibly more complex.�
Feb 6, 2016
JRP3 Agree. Unnecessarily complex idea. Just make wheel covers optional and easily removable.�
Feb 6, 2016
Red Sage I believe the BOLT was designed as an ICE replacement for the SONIC to compete against Honda FIT, Nissan QUBE, Kia SOUL, and Scion xB... But someone at GM decided to make it fully electric instead once Tesla Motors made a big splash in the automotive industry. And BOLT is definitely designed to NOT sell in numbers that would endanger either the Chevrolet CRUZE or MALIBU.
Excellent argument that I, nevertheless, must disagree with... In case the EPA pulls a fast one, and decides to change their testing procedures in a manner that greatly favors ICE or ICE Hybrid vehicles, Tesla Motors must make sure that there is far more energy reserve than is absolutely necessary to reach their range target. Bare minimum for Tesla Model ? should be 60 kWh capacity with 48-to-54 kWh useable, to ensure a 200+ mile range in the Real World. I'm talking 194-to-243 Wh per mile on average in 'eco' mode... And perhaps 216-to-270 Wh per mile in 'normal' mode. Though really, I pray for a 100 kWh battery pack that allows 250 miles of range even at 330 Wh per mile.
Sure, if Tesla Motors target were the bottom-of-the-line varieties of 3-Series and A4, that might work. But I seriously doubt that Elon Musk believes a 180 HP drivetrain would be 'compelling'. I expect that the base configuration of Model ? will need enough capacity to both get the range, and power a capable motor. Something that would be on par with 335i/340i in performance, for 320i/320d money. That makes the line in the sand as a 60 kWh battery pack, paired with a 300+ HP motor.
+42! Quoted for Absolute Truth!
Correctomundo! Plus, that happens to be a weakness that would be shared with Hydrogen Fuel Cell Electric Vehicles, as well as the aluminum oxide catalyst fuel cell notions that people have kept coming up with as 'range extenders'... There is absolutely no need to add such disadvantages to a fully electric car.
Yup! Such systems are best suited to stationary applications instead. There are places in the world where they may work well, and others where they barely work at all.
When GM gets off their butts and makes a fully EV version of the ELECTRA, that can have side skirts. They'll go great with the Landau top, whitewall tires on Daytons, and curb feelers.
Here the problem is... Tesla Motors has already learned that attempting to allow a bargain basement entry point for their cars does not work. After delivering around 2,500 of the Model S, their 10,000 outstanding Reservations had not dropped to 7,500. It had grown to 13,000. And the take for the Model S 40 was still less than 5% of the total. People who were interested in driving electric opted primarily for the highest available capacity. They will do the same with Model ?. The baseline threshold is 200+ miles of range with Supercharger access and compelling performance, not <~150 miles without Supercharging or breakneck first impressions, as some continue to argue.
Agreed. Estimates for Tesla Motors' current internal cost for battery cells ranges from $180 per kWh to as high as $240 per kWh. Assuming a 30% initial improvement in cost by way of the Gigafactory, that would drop to $126 per kWh to $168 per kWh. But Elon Musk is often misquoted, because the 30% amount is strictly an improvement based upon having local supply, instead of having components manufactured in Japan, shipped to China for assembly as battery cells, then shipped to Fremont for completion as battery packs. He has since stated that he expects the decrease in cost to be closer to the 40%-to-50% range. That is once a change in chemistry, improvements in design, and a new cell format are implemented.
Correct. This is the sort of comparison that people who lobby for low capacity battery packs never seem to get. They never recognize, for instance, that the Toyota RAV4 EV actually had a 50 kWh battery pack, with slightly over 40 kWh of available capacity for driving. And that car only had a 103 mile EPA rated range. This, even though it was around 400 lbs lighter than the Model S 40 -- which got a 139 mile range -- and the RAV4 EV had the best Coefficient of Drag for any SUV offered in the US.
Further, people who expect they will get 'more range' with a vehicle that has a lower power electric motor that is 'not performance oriented' are similarly proven wrong. The RAV4 EV only had a 154 HP motor, while both the Model S 40 and Model S 60 had 300+ HP motors. The old-school strategy of using a wimpy motor in a front wheel drive configuration to significantly improve economy doesn't apply to electric vehicles, because they are vastly more efficient than ICE already.
Yes, but that was a mistake. Their cars were designed to meet certain EPA range goals under the 2-cycle testing scheme. But they achieved lower results because there was a different, 5-cycle test in place by the time of their release. So, the Model S 40 had a 139 mile range, instead of the 160 mile range they hoped for originally. Tesla Motors is fully aware now that it is the capability of the vehicle that is most important to Customers. Not its relative economy due to price point. They fully expected the Model S 40 would be their best seller. They were wrong. Instead, the grand majority of buyers got the Model S 85. They will not make that mistake with the Model ?. Tesla Motors will make the greatest possible amount of range available for $35,000 in the base configuration. I expect that will yield in the neighborhood of 250 miles range.
Tesla Motors cannot bother to worry about those people who can't afford their cars at all. They build Premium cars. They will be marketing the Model ? to people who are considering Cadillac ATS, AUDI A4, Jaguar XE, Lexus IS, and specifically the BMW 3-Series. Those cars are almost NEVER available on the lots of an 'independent franchised dealership' in their actual, manufacturer specified, base configuration. Instead, they will be loaded to the hilt with luxo packages that push their prices several thousands above the mark. You will be able to order a Tesla Model ? with ZERO options if you want. That is the proper option for those to whom $1,000 'makes a difference' -- they must exercise self control. Meanwhile, Tesla Motors will offer compelling products.�
Feb 6, 2016
Twiglett That was a mega post, but worthwhile reading nonetheless.
The very last point is what I keep picking up in these conversations about the Model 3
So many folks keep connecting "mass market" to Ford or GM, but as you mentioned its premium not run of the mill.
The other popular misquote is that the Model 3 will be "affordable", when most of the quotes I have seen are actually "more affordable" meaning more affordable than the Model S or X
Not affordable like a Corolla�
Feb 6, 2016
wdolson The Model 3 might end up compared with mid-size luxury cars, but I expect a large number of buyers will be moving up from much less expansive cars. I believe something like 1/2 of Model S buyers have never driven a car worth more than $60K before. (I'll be one of them one day, my current car cost $22K new.) Because of Tesla's technology, performance, economy, etc. there are a lot of people who stretch their budgets to buy one. The number of people who can afford a $100K car, but it's either a major stretch of their budget, or they just choose to drive cheaper cars is very limited, however there are more people out there driving Camrys and Fusions who could afford a $45-$50K car (maybe with some budget stretch), but choose not to.�
Feb 6, 2016
Red Sage Twiglett: I agree. It takes a tremendous amount of manufacturing capacity to offer a vehicle such as the Toyota Corolla, Volkswagen Golf, or Ford Focus in numbers approaching or exceeding 1,000,000 units per year, worldwide. It takes similar capacity to offer a Chevrolet Silverado, Ford F-Series, or RAM to satisfy the needs for full-sized pickups in the US. Those that have been literally complaining about Tesla Motors starting on the high end, saying they should not have brought out anything until they could compete in volume with a full product line of vehicles under $25,000 should never be allowed to manage any company. I fully expect that those who would ordinarily be shopping for Camry, Accord, Fusion, Altima, Malibu, Sonata, or Optima will (if given the opportunity) stop by a Tesla Store on a whim to test drive the Model ?. And the result will be that Toyota, Honda, Ford, Nissan, Chevrolet, Hyundai, and Kia dealerships will see that their bread-and-butter vehicles will take quite a bit longer to move off the lot than they are used to seeing. They'll blame it on the economy... Until they realize how quickly sales are increasing for Tesla Motors vehicles.
wdolson: I agree. Just as people who typically would not have purchased anything beyond the 40,000-to-$50,000 range chose to go up-market to the Model S... Those who would typically only spend in the $20,000-to-$25,000 range will choose to go up-market to the Model ?. One thing that is interesting is that while the average sale price for a new car is over $31,000 currently, most new cars sold in the US are around $22,000. I believe that if Tesla Motors is able to cut their internal cost to below $100 per kWh, they will be able to offer a 60 kWh capacity vehicle for about $25,000.�
Feb 6, 2016
Ross1 Easily removable means also easily attachable.
What you do is open the back doors and clip them on. At 100 mph. Easy.�
Feb 6, 2016
CTemp222 However that may be a decade in the future.�
Feb 6, 2016
wdolson I had a car many years ago with removable skirts over the back wheels. They had to be removed to change a tire, but was otherwise only decorative. The mechanism to remove the skirts got horribly gunked up with road gunk to a point that getting them off was a messy chore. I wouldn't want to remove skirts from the wheels on my car after getting off the highway when it's raining.�
Feb 7, 2016
Red Sage There was some guy, supposedly an 'expert' in battery technology, that published a paper in 2014 that lambasted Elon Musk, the Gigafactory, and the very concept of battery electric vehicles as a viable option for the present or future. His primary point was that electric vehicles were simply far too expensive, and that until the price for the technology could be brought down to below $173 per kWh, it wasn't worth the effort. He estimated it would take about ten years for that to happen.
Which was rather strange... Because the most optimistic estimates for Tesla Motors was that they paid Panasonic around $180 per kWh... And that if Tesla only got the 30% improvement, that Elon said was the minimum expected, from the Gigafactory, that would put their cost at $126 per kWh. Considerably below the threshold that the 'expert' said was necessary to validate battery electric vehicle technology.
Some here are proud to say they don't believe a word that Elon says. I would hope they are not quite so critical of JB Straubel. He has consistently stated that there is an annual improvement on cost for Lithium-ion battery technology at a rate of roughly 7% per year. Well, by my calculations, if the Gigafactory does yield $126 per kWh to start, that means that within four years of its opening, Tesla Motors' internal cost would be as low as $94.25 per kWh.�
Feb 7, 2016
CTemp222 Yes with recent happenings on this forum it seems that some people do have a beef with Elon, but that's interesting, do you know where I could find this "experts" paper? And based on your calculations being below $100 per kWh does seem reasonable within five years or less.�
Feb 7, 2016
Red Sage I'll have to check my archives... I'm pretty sure it was discussed at length on the currently unavailable Tesla Motors Forums. Here are a couple of articles that cover the general economic status of the Gigafactory, and how it would affect pricing for battery packs:
Tesla Motors, Inc.'s Gigafactory May Be More Revolutionary Than We Realize -- The Motley Fool
Tesla's Battery Gigafactory May Achieve Nirvana: $100 Per Kilowatt-Hour, Report Says�
Feb 7, 2016
ohmman I posted this upthread, and happened to run across this video today. Not exactly the same thing, but pretty fun to watch regardless. (It was done using compound video).
[video=vimeo;106226560]https://vimeo.com/106226560[/video]�
Feb 7, 2016
CTemp222 Now that would be scary!�
Feb 7, 2016
AudubonB A lazy afternoon in Rio de Janeiro or Mexico City.�
Feb 7, 2016
1208 Vietnam doesn't need your Hollywood fakery
�
Feb 9, 2016
Rashomon Cameras Replacing sideview mirrors: just a matter of time.
See articles.sae.org/14468
the D.O.T. Can issue regulations that supersede state law. Congress has already delegated that authority.�
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