Originally Posted by Yugo
Excuse my ignorance, but I never really understood the engine weight comparison between the S54 and the S65. The S65 is 33lbs lighter (iron vs aluminum), but on the other hand the E90/92 as the whole car is 300lbs heavier than the E46...so what's the big deal that the engine is lighter?
First, the car would be 333lbs heavier if the engine wasn't lighter (using your numbers). Lighter is better.
Second, Acceleration is a function of power (to the wheels), weight and traction. Although the engine has little effect on traction (smooth power delivery helps, but both engines have that in spades), but all else equal, more power and lighter is better.
If you can add power and save weight, that is good, so why wouldn't people be excited about BMW's new (six years ago) engine being significantly more powerful 414 vs 333, and also lighter?