dsthez

For all you ap1 owners who installed 17" wheels dose the car seem slower straight line? Even if the wheels are lighter than stock ap1 like the rpf1, the mass of the weight is further from the center? Experience?

s2000Junky

No, nothing perceivable. Remember you are losing some of the sidewall weight moving down a series as well. Thats even further out.

Rx8toS2k

I had some 18" 5Zigen 5ZR rim and switched back to the 16" stock rims (Enkei) and felt a noticeable difference in acceleration. Subsequently, I switched out to 17" Volks TE37 and felt no drop off in acceleration maybe in fact feels a little bit quicker since its lighter.

s2000Junky

18's are typically a lot heavier then 17's. I'm not surprised. Moving from a 16 to 17 is totally reasonable. Especially when you consider it became an OEM improvement later on. OEM 17's are pretty heavy too 20+ LB, its not hard to find a 17" lighter than that, comparable to the factory 16's.

starchland

Did notice abit going from 16 to 17 . 17" tire is a bit heavier . Overall the extra rotating mass is roughly 20 lbs added in my case.

s2000Junky

...Or you could pick up a typical 17" 8/9 RPF1 with factory 215/245 and have a lighter then factory 16" package. Depends on what you get, but you will never get a lighter package out of 18's

Rx8toS2k

My 18" 5Zigens weighed around 25-26lbs then switched to the OEM 16" which was around 17-18lbs and down to the 17" Volks TE37 at 15lbs. So the weight difference in this case was noticeably felt.