I have heard nothing but good from RF to non RF especially on comfort and handling. I am planning to ditch my GY RSA RF on my 17 S-Lites probably with Kumho SPT or ES100 205x45x17.

Any member who would be willing to share any measured acceleration gains from RF to nRF?

Thanks.

 

Reducing unsprung weight by going to non-runflats will noticeably improve acceleration.

 

Get lighter wheels when you get the new tires

 

Changing tires will affect weight a little. Lighter is good but so is the softness of the rubber. Soft rubber allows for better traction as long as throttle is applied smoothly. LSD helps.

See this post about some differences in 0-60 times with various MINIs with various wheels.
https://www.northamericanmotoring.co...ad.php?t=28002

There are many factors but it's a small time difference and alot of improved responsiveness due to loss of weight.

Within the same tire size there is some variation with different non runflat tires. You stand to loose alot more weight by going to a light aftermarket wheel. The S-lytes are about 25+ pounds each and aftermarket rims are about 14+ pounds each(some lighter, some closer to 20).

Tire weights in 205/45-17.
Goodyear RS-A EMT Runflat 22 lbs.(High Perf All Season tire)
Kumho Ecsta SPT 21 lbs. (Ultra High Perf Summer tire)
Yokohama AVS ES100 21 lbs. (Ultra High Perf Summer tire)
Kumho Ecsta AST 20 lbs. (High Perf All Season tire)

and
Kumho Ecsta SPT XRP Runflat 28 lbs. (Ultra High Perf Summer tire)
Pirelli Eufori@ Runflat 22 lbs. (Ultra High Perf Summer tire)

Depending on which tires you use the weights are pretty close, about 1-2 pounds each.

 

Great info...Thanks!

 

I went from my S-LItes w/ Dunlop RF to a Kazera w/ Kumhos. (both 17") My Kumhos aren't broken in yet, and I really don't have a scientific study. However, my new set is 4 lbs lighter per wheel than the old set. I'm not expecting anything major in the acelleration department. However, I do notice increased comfort - every expansion joint doesn't bash my kidneys.

If I were at the track, I would go w/ the lightest wheelset possible (ex. 17" wheel under 16 lbs), and a tire w/ a light carcass.

The Tire Rack can really help you out depending on what your goals are. Have fun!