Anyone know what an 07 or 08 steptronic Z4 coupe puts down to the wheels? Also, regarding the step cars, anyone go about installing an (external) tranny cooler? In other makes, it is a very common aftermarket upgrade in auto cars that see any type of performance driving. Thanks!

I don't know but, I drove my co-worker's 2008 Steptronic Z4 3.0si Roadster yesterday and hers pleasantly surprised me. It felt great. Didn't feel much if any of a perfermance compromise when using the paddle shifters. I can't wait to get my Z4 M Coupe!

i dont think anyone's ever dyno'd an auto 3.0 but the steptronic tranny in bmw still suffers from typical drivetrain loss as other cars. it's not as advanced as the dsg system in audi/vw which puts down numbers close to its manual counterparts but i would imagine its in the area of 20% - 30% from crank. are you referring to to 3.0 or 3.0si btw?

Thinking of 3.0si specifically. I figured that there were a few things going for it, though. Namely less parasitic loss b/c of electric power steering, better final drive, some under-rating of crank hp, etc.