I knew so much less 10 years ago than I do now. I had a 2003 M3 back then that I used on street and track. I went from heavy street wheels and tires to heavy track wheels and tires so didn't really feel much difference. But I was less in tune then than now. Fast forward a few years and I picked up a 2005 330i as a daily driver. Stock wheels and tires and when it came to my first winter I got a set of BBS RK and kept those for summer and put snows on the OEM rims. 4 months later when I changed from OEM to BBK it was amazing the difference. Without a doubt I could feel the improvement in acceleration as the significantly lighter wheels "spun up" so much quicker.

I remember reading a "rule of thumb" that 1 lb rotational / unsprung is loosely equal to 7 HP. Drop 3 lbs from your wheel / tire combo and it could be like picking up 21 HP (thought I don't remember that rule suggesting torque figures). This VW information supports all of what we are talking about, though I don't know we can draw direct lines to numbers like 4x or 7hp.

I have a set of Technology hollows on my 993 and ordered a set of BBS RS-GT that should be here any time now. While the hollows are lighter than solids, the BBS are lighter yet.

 

Thanks Ron, that is encouraging. I will also look into the lightest practical tires, and lugs.

I once paid quite a bit for titanium lugs on my Fcar. I don't think they made a noticeable difference, but wow are they light.

I figure that even if I don't feel any benefit, it won't hurt, so I am no worse off.

 

I have hollow twists on my 95 C4 and I love the way it drives. Have not had heavier wheels, but a fellow rennlister with a 95 C2 really liked the pull of my car. It is a strong stock motor with a Steve Wong chip and at 125k it made 250 WHP on a dyno.