I'm not driving rear-only, ever. Did that once, not again.
I'm not paying another $11,000 to get the dual-motor version when all I care about is the front. That's a whole 'nother car worth of money.
Keep on building California cars, Elon. I'll buy one as soon as it fits both my budget and my climate. Some models fit one or the other, but nothing does both.
However RWD is actually better... assuming the car has a good front/rear balance near 50%... like the Telsa. Any FWD gets LESS traction when climbing than driving on the flats. A RWD gets MORE traction when climbing than driving on the flats. Of course when driving down hills you can always throttle off and just use the brakes.
Additionally your limited traction budget in a RWD allows the front wheels to be dedicated to steering only. On a FWD you have to spend part of your traction budget on acceleration.
So get the RWD, it's cheaper than AWD, and better in the snow than FWD.
Personally I'd rather have oversteer, which is easily compensated for (a bit of steering and let off the throttle), but doesn't impact your path around the corner. It's also quite fun.
Understeer on the other hand does impact your path around the corner, the car plows straight ahead as you ask too much of it. Additionally the threshold for understeer is lower since it's the front tires trying to handle acceleration and steering. So a RWD has more traction at a given speed than FWD.
Keep in mind that the that RWD in terrible in the snow comes from things like empty pick up trucks (no weight on the rear wheels) or old American sedans and sports cars that had large engines in the front and not much weight out back. Generally even with a perfect 50/50 weight distribution that the RWD is going to have the advantage.
If you're used to understeer (FWD loss of traction), then for safety reasons, you should stick to understeer. If you're used to oversteer, then stick with oversteer.
Its not like it snows every day. Your opportunities to practice loss of traction are few and far in between.
But if it snows often there's a simple choice. Do you want to lose the ability to accelerate (oversteer), or do you want to lose the ability to accelerate and steer (understeer)?
Even a single hour in an abandoned parking lot should get you familiar with either, and it's quite instructive to spend significant time over the threshold of sliding to help prepare you for the occasional surprise on real roads.
You don't even need "good" weight distribution for RWD to hill climb better. I live on a hill. My RWD pickup goes up it better than the FWD wagon which has near 50-50 weight distribution.
The AWD wagon (same model and generation running the same exact tire) and the pickup in 4wd will run circles around anything with two driven wheels though. All three vehicles are old so no limited slip diffs or traction control so it's a fairly scientific comparison.
>Additionally your limited traction budget in a RWD allows the front wheels to be dedicated to steering only. On a FWD you have to spend part of your traction budget on acceleration.
Basically anything that makes a car handle well in the dry makes it handle well in the snow. Everything behaves the same but your coefficient of friction is less.
My 2006 era RWD car has the manufacturer's optional stability control, and I'm constantly impressed by how effectively it keeps the car in-line in snow. Even on long, sweeping turns, where it's hard to know when you're beginning to slide. This is without any kind of steering control, with only engine power limiting and individual-wheel braking.
Much more important, is to have proper tires for the season. Even if you don't experience snow, you need tires with the appropriate temperature ratings. Summer tires will turn rock-hard in freezing temperatures, and lose a lot of grip. Even on bare pavement.
The US price is not that bad!
My parents used to do that so they could drive our Toyota Hiace in winter. As a bonus, there's fresh sand for the sandbox every spring!
Anyway, if grip is important, you might as well go for AWD. The difference from RWD to FWD is tiny, if any (I also live in snowy-lands and have driven both). But going to AWD, especially with the dual motor AWD you get with EVs, is a world of difference and probably worth the upgrade.
In my experience, the most common problem with snow is getting enough traction to move out of parking spot or up a steep incline. Like most AWD vehicles, the AWD Tesla has an open differential which does not help much in these scenarios. When traction gets dicey it behaves like a 2WD with torque spread between one front and one rear wheel.
So, despite "everyone doing it" by your words, I was just unaware of how it worked because it's not relevant to me. My VW syncro van has both forward and rear locking differentials anyway.
Friction is non-linear so you're going to need very fast feedback loops on the brakes to simulate a locked differential. One can't just apply a fixed amount of braking to every wheel and have stuff magically work out.
The main issue is while limited slip differentials do work, they are expensive, add weight, and they add friction. So the software solution gets you better MPG, better HP, and more control. There's many different names for it, traction control, torque vectoring, traction assist, etc.
Even Subaru who bet the heaviest on AWD (selling only AWD until they sold the BRZ), and had one of the best respected AWD systems is moving to open differential with the brake assist, on at least some of their cars. Not sure about the STI and WRX though.
Some more expensive sporty cars have limited slip differentials, mostly to avoid inside drive wheels spinning in sharp corners. It helps in the snow as well of course.
My Subaru WRX had a limited split in the center and rear, so it had three wheel drive when slippery. The higher end STI had an option for a front limited slip differential. Apparently when rallying on tight courses they would pick three wheel drive because it allows rotating around the inner front wheel for very sharp turns. It's great fun, plant a wheel (literally motionless), the car spins around it, until you let go of the wheel and the car launches in that direction. On more open courses the rally drivers would select the four wheel drive to get the most of the traction when going mostly straight.
The Tesla AWD is actually 4wd, but under software control. I wouldn't say as nice as a locking differential, but pretty close and able to get some power to all four wheels.
And to my chagrin, I’m deep in a worm hole learning a whole lot about the Tesla AWD system tonight.
On an ICE vehicle the only difference between rear and all wheel drive is a differential and a drive shaft. Maybe I don’t know enough about electric vehicles, but “dual motor” sounds a lot more expensive.
You need three differentials for AWD as you first need to split the power front/back and then right/left in each axle. That's two more differentials than in just RWD or FWD. You also need to package all that together with a gearbox. That's why many manufacturers don't even offer an AWD option, and having both FWD and RWD versions of a car is very rare if it happens at all.
Meanwhile Tesla already builds all their cars to have two independent motors front/back each with their differential. They could very easily build a FWD car right now just by omitting the rear assembly. The cars are apparently even already designed to work with just the front motor for reliability so even the software update would be simple.
And building AWD cars by having two electric motors is almost surely not more expensive than the ICE way. Electric motors are much simpler than combustion ones and you eliminate all the mechanical parts needed to split the power between the axles. Control also becomes much better as the software gets to adjust power independently to both axles.
You need a differential for each driven axle. The expense of the extra motor and motor controller vs the expense of the transfer case (or FWD based equivalent), and drive shaft (not really all that expensive) is probably close to a wash or slightly in favor of the ICE vehicle. I don't think you understand how cheap and commoditized drive-train parts are. Like really, these assemblies are cheap and almost go together like legos (from an OEM perspective). It's not like you burn tons of engineering hours making a FWD or RWD vehicle into AWD so long as whatever floor pan you're working with was designed to be AWD compatible.
Someone like Sandy Munro that does detailed costing would be able to answer this definitively for a few models. But it will most likely depend on the actual implementation to see what ends up cheaper. According to Munro Tesla has a big advantage in the cost, weight and performance of the motors right now compared to other EVs so that might be enough to tip the scale. I'd love actual data though.
The motor controllers are probably the more expensive part, although most of the cost there is engineering design cost (much of industry doesn't use fancy motor controllers needed for a car, and cars use high power MOSFETs which are rapidly evolving tech). Tesla designing them in house will eliminate much of the cost over enough volume.
With an electric car you don't save anything with RWD vs FWD, you end up with poorer steering, poorer acceleration, and worse hill climbing, especially if it's snowy or icy. Nor is it cheaper to produce.
As a result even electric cars intended for city use like the BMW i3 and Renault have RWD.
On the model 3 the rear motor is larger and a permanent magnet motor (which is more efficient) and the front motor is an induction motor. So a FWD would have less power than the RWD, and it would also have less range than the RWD. Not sure Tesla would want to try to sell a car slower (because FWD), slower (because of less HP), and with less range (because of efficiency) without it being cheaper to produce.... just to have a FWD.
They were aware of this problem even in the 1990s.
The fact that people abstractly know a situation exists does not mean they will handle it correctly.
Also, remember the issues with "racist" face recognition systems that were trained on non-diverse data sets?
It's not like google engineers forgot black people exist, but I think it's not trivial to pay the proper attention to some problems if they are outside of your daily experience.
While their ability to go forward is much better, their ability to stop is very similar.
I see lots of SUVs driving stupid fast on snow.