Was the real, nearly identical 335i vs. 335d not close enough that you want to toss around purely hypothetical situations such as you just wrote? 1/4 mile 14.2@99 for the diesel, 13.5 @103.8 for the gas. As for your question re: 400hp, 2000 lb car? At 60mph, it'll accelerate at ~1.2 ft/s^2. At 100mph, .74 ft/s^2 (ignoring wind and windage losses, of course). (oops, screwed up the units. That should be 1.2 g, and .74 g, not ft/s^2). Any chance you could do a similar calculation from torque? I didn't think so.