Given the nature of the S, would there be a noticeable difference in ride quality between 17" and 18" assuming the same wheel and overall tire diameter? How about going from the AP1 stock 16" to 18"? Sorry for the noobish question, just unfamiliar with this facet for now.

 

If your suspension stays the same the 18's will ride a bit rougher due to the shorter sidewall. It also depends on the tire you choose and the weight of the wheels to some extent.

 

I concur with Manga.

there are several deciding factors such as: wheel choice and tyre choice. however the main pros and cons are:

Pros

Better Grip and road holding
Look a lot better IMHO
Braking performance improved

Cons

Speedometer error (less then -2 mph)
Reduced acceleration (0 to 60 takes generally 0.1 seconds longer)
decreased mpg (1 mpg)

There are others but I think this is the main points covered. most the drawbacks/benefits are marginal anyway and unlikely to have an impact on daily driving.

Speaking from experience I run 18" buddyclub (pictures: https://www.s2ki.com/s2000/topic/107...#entry23079755 excuse the poor quality and rotation.)With Falken 452s all round and I have to say I love them think they look ace and suit my driving style, cant report any real negatives, especially with it being my daily driver.

A good article to have a quick read of: http://www.caranddriver.com/features...d-tires-tested

Hope this helps, sorry for the long winded nature of the reply.

 

The real benefit to 18's is you can get wider wheels and wider tires. Good tire options for 17's get limited once you go wider than 255. 18's however have a lot of good options since many Porches and other cars come with 18's stock and 285 or 295 tires.

 

Right now it's lowered on Megan racing springs(I plan to upgrade to something better), and the ~1.25" drop is another thing pushing me more towards 17's just to avoid fitment issues.

 

There shouldn’t be any difference in fitment between 17 vs 18 as long as you size the tires correctly. The overall diameter will stay the same. If you go from 245/40/17 then you would go to 245/35/18 for the equivalent. But I agree for a different reason, that there is little need to go up to an 18" unless you plan on exceeding 255 tire width, simply for the sake of optimum tire sizes/profile.