Everyone appreciates a speedy acceleration, when merging into highways or getting out of the way. Its far more important to be quick on acceleration than to have a top-speed.
Tesla Model 3 isn't breaking any records. I can think of plenty of cars in the price range that is that fast actually (and as you noted, the WRX definitely undercuts the Tesla significantly in price).
But in my experience, zero-to-sixty in 6 seconds is a good speed. Its not "slow", and should be fast enough to feel somewhat luxurious.
The Subaru WRX, and Ford Focus RS are performance-oriented cars after all. They happen to also be good daily drivers. Performance-oriented drivers will stick with Subaru WRX / Focus RS because the real time performance people care about is the Laguna Seca lap-time (or other lap times on famous tracks)... a combination of cornering speed, handling, acceleration, AND braking to test all aspects of the car.
Zero-to-sixty in 6-seconds isn't amazing, and the M3 likely won't do Leguna Seca very well (Model S overheats for example and is forced to slow down. Its probably something to do with electric motors)
https://forums.teslamotors.com/forum/forums/model-s-laguna-s...
And there's the Subaru WRX, beating out the Model S on Leguna Seca by a few seconds, let alone the Model 3. So yeah, people who care about overall performance aren't going to be getting any of the Teslas any time soon.
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So the real selling point is the electric car value. The question is if the Model 3 can actually deliver. Its still a concept-car, a lot of things are going to change between now and "late 2017", probably 2018 when the cars actually come out for most people.
The GM Bolt is launching this year. BMW is launching their electrics soon. Tesla has a leg up inside of the electric market IMO, but I'm curious to see if the M3 actually gets widespread adoption.
And no, I don't think a refundable $1000 deposit really counts as a real sale.
Frankly, zero-to-sixty in 6 seconds WITHOUT shifting and with 100% standing torque is kind of... awful actually. I suspect the opposite, when a ICE engine hits 4000 to 6000 RPM and the torque kicks in, you'll be accelerating far stronger than the smooth acceleration a Model 3 will give you.
Consider a jerky zero-to-sixty with three gear shifts on your typical manual car (say... Ford Focus ST or RS), in contrast to the smooth acceleration from like a Nissan or a Subaru WRX. You definitely feel more G forces from the Focus, while the WRX only beats the other car because the CVT engine never has to "stop" for the gearshift.
Similarly, I'd expect the smooth acceleration on the Model 3 to have less peak G-forces than a manual car. It will happen to be a smooth and constant acceleration, but there's a HUGE difference in Model 3 vs Model S acceleration. And I hope people aren't getting their hopes up.
Car and Driver just released a review of the STI vs Golf R vs Focus RS. Both the R and the RS had 1-second-slower 5-60 runs vs 0-60. Why? Because they don't have clutch-dropping launches. The STI was vastly worse -- 2 seconds slower 5-60 vs 0-60. That's right -- 5-60 was ~6.8 seconds vs ~4.8 seconds 0-60.
Remove the ICE drivetrain dump launch and suddenly ICEs don't feel so quick. A Model 3 that can do 6 seconds 0-60 might sound slow, but is faster than it sounds, and likely feels so. It laughs at 5-60 because, in the electric world, that's 5 fewer mph it has to accelerate through. In the ICE world, we're talking about a lot of revs we need to pound through before the exhaust gasses spin up the turbo enough to create adequate boost to force air into the engine to create powerful enough explosions to try to create enough power in the itty bitty engine. That's, quite simply, a huge amount of time lost.
Even in my R, I can mash my foot to the floor and wait a second or two before acceleration is truly impressive.
Which is crap compared to the naturally-aspirated 3.2L I6 in my BMW. Which is crap compared to the same engine with individual throttle bodies where there's less distance between the outside air and the valve controlling the intake. Which is crap compared to a much larger engine, like a big V8. All of which are crap compared to a properly-tuned electric motor. (yes, in the interest of efficiency, you may find that many electric motors are programmed to have really laggy throttle response; even so, BMW brags that the i3 is quicker 0-30 than their own M3, even though I found it to be horribly laggy in throttle and deceleration response)
Even the Volvo XC90 managed to slide under the bar at exactly 6 seconds. You really have to work hard to move downmarket enough to still be over 6. Sorry Kia owners.