I think we all remember enough high school physics to know that lighter wheels will improve acceleration, but I was slightly surprised by the effect. I just replaced the standard S-lights ('06 MCS, 205/45-17 Kumho ASTs) with some OZ wheels with Kumho LE Sport tires. All up weights were: 45.8 lbs for the stock wheels, 41.6 for the OZ (includes balance weights, valve stems, etc.). I don't do many 0-60 runs, so I don't know what the ultimate effect might be, but I was surprised by the difference in everyday, mild-mannered driving. With the stock wheels, the car always felt a little boggy off the line, such that I always had to give it a little more gas than I really wanted and every start felt like a racing start. Now it just bites cleanly and motors off smoothly, making for a much more pleasant driving experience. Point of the story - if you are thinking about lighter wheels but think it is mostly about ultimate performance (as in competition), you might have another reason to justify the switch (YMMV!).

 

This topic of lighter wheels giving better responsiveness, braking and acceleration has been discussed many times before.

A wheel upgrade and non runflat tire upgrade are some of the easiest and best modifications you can do with the MINI.

for more-
http://www.*********************/for...#axzz20WvL0Dmd

http://www.tirerack.com/wheels/tech/...jsp?techid=108

http://forum.mazda6club.com/wheels-t...rformance.html

http://forums.nasioc.com/forums/showthread.php?t=354033

 

Having just toured Maine, NH, and Vt over several days I would add that another benefit of light wheels is the ability to track through frost heaves without upsetting the car.

This is particularly helpful when said frost heaves are on the apex of a fast sweeper with nowhere to go but down the mountain if things get too hairy!

I would not recommend my setup for grand touring comfort mind you - it's too stiff for that.

 

Lighter wheels (i have light 15's and the lightest oem 16's) do make the car feel more nimble....a better driving experance...less like a truck that refuses to turn due to heaving spinning weights on the axles.
Simply put, while reducing spinning weight has 4x the effect of removing weight from the body for accleration, in daily driving, it FEELS like more due to the handling improvement.
Anybody that has gone from heavy cast 18's to a light rim/tire can feel and speak to this.