The laws of physics says F=M*A (much, much more) (archive)

Vehicle weight, gearing, losses in getting the torque from the motor to the rear wheels, and the capability of a car to actually make use of that torque at the interface between the wheels and the ground (that is, to avoid wheel spin) all contribute to the car's actual acceleration. But if you know both (1) the torque at the interface between the tires and the ground and (2) the vehicle weight, then you know the vehicle's instantaneous acceleration. And if you know a vehicle's torque curve (at the tire/ground interface), you can, in theory, accurately predict time-to-speed. This is true for M3s and S2000s alike.

All other things being equal, a car with more torque will out-accelerate one with less torque. But almost everything between a BMW and an S2000 ISN'T equal. So it's very, very risky to extrapolate the E46 M3 0-60 time from that of the S2000. On the other hand, the E46 M3 will be an evolutionary change from the E36 M3 (and from the E39 M5). Extrapolating from the accereration achieved by those cars isn't nearly as risky. And that extrapolation tells us (1) that and E46 M3 with a 3.4L motor will achieve approximately 260 to 270 ft-lb of torque, and (2) given that amount of torque (and assuming the vehicle weight is about 3200 pounds), the car will probably do 0-60 in about 5.2 to 5.4 seconds.

In order for horsepower to be useful (in terms of performing the physics), you must first convert it to torque. So why use HP in the first place?

: : ...they're not all that hot. 380Nm of torque translates to about 277 ft-lb (horsepower doesn't mean diddley). That's a super torque/L figure (86.6 ft-lb/L for a normally aspirated motor, but the torque/vehicle-weight figure is only so-so for a performance car. Read: This level of torque won't an M3 to the stratosphere.

: : AND, considering that this is an ultra-maxed-out motor, you can bet the farm that the E46 M3 ISN'T GOING TO COME CLOSE to this torque/L figure. 270 ft-lb is going to be the MAX for a 3.4 L motor. And if it's a 3.2L motor ...

: : In either case, kiss sub-5.0 (or even sub-5.2) goodbye!

: : Billy
: : : Nervous? Should be.

: : : 3.2L 370hp@7900 and 380Nm of Torque.

: then how can we explain the new honda 2000 which does 0-60 in under 5.4 sec, but has only about 160 ft lbs?? Seems to me those 240 ponies have something to say about it.

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