Take a look on the Model S design site. It will be a similar effect. Going from 70 to 70D takes the S from 5.5 to 5.2 .
A little bigger battery and dual motor a lot better.
It will be the same effect and to scale.
ALSO, don't put it past Elon to pull a fast one with the world of competition watching. So for now he says 6 seconds. The competition banks on that and puts out something similar or just under it at 5.8 on their base model. THEN the second reveal comes along and he says, oh by the way, we have improved it to 5.5.
We just saw this effect. He told everyone that the Model 3 would have at least a 200 mile range.......Bolt is announced with 200 mile range.....reveal #1 comes around and surprise it gets 215 range. ....Now Chevy is scrambling to lift the range on the Bolt. (Source: InsideEvs)
Yes, getting about double the torque to all four tires without greatly increasing the vehicle weight increases acceleration significantly, according to Newton's Second Law of Motion.
I once owned a Fiero GT, which internally was basically a lighter-skinned, two-seat Chevy Citation with many of those components reversed front to back. Pontiac sneaked approval of it through board meetings as a "two-seat commuter car."
GM once had a prototype Fiero with a V8 in the back at the Milford Proving Grounds. Safety inspectors did not like the idea of a car doing wheelies. (Too light up front, too much torque in back.)
More fatally, Duntov and Chevy did not like the idea of a product beating the 'Vette in the quarter mile. Not gonna happen.