s2kdriver80

When people ask if they should upgrade wheel sizes to 17 or 18 inches for the track or for better performance in general, I see others telling them to stay at 16 inches. However, I see that the AP2s are fitted with 17 inches from the factory, yet they handle just as well (and are even more stable, but probably the revised suspension plays a role as well) or some may say even better. The AP2 doesn't suffer from worse acceleration either. 18 inch wheels are commonplace on higher end sports cars and yet they perform very well.

If one could find 17 inch wheels that weigh the same (or even lighter) as the stock 16 inch wheels, find wheels that have a favorable moment of inertia (as I assume placement of wheel mass affects acceleration), and fit them with lower profile tires that result in same overall wheel/tire diameter, how would this setup perform worse than stock? The lower profile tires and the probable wider contact patch would provide better grip performance and put more power to the ground, and the larger wheels would satisfy the aesthetics department.

Just wondering since I'm not that well versed in the mechanics of wheels/tires and their effects on performance.

Adampops

For normal driving and even a weekend track car, I couldn't see this extra inch making much of a difference and the extra contact patch of the wider tire would probably increase performance more anyway.

ZDan

My approach has been maximum width tire on minimum diameter wheel. This results in cheaper wheels, cheaper tires, and *generally* should mean less rotational inertia even if wheel+tire weight is the same.

I'd bet that for the same width and same diameter tires, going one profile lower with a larger diameter rim might not be as much of a benefit as you might think. Might not be any benefit at all.

When it comes down to it, the cars I tend to like are small enough that they don't NEED giant wheel diameters to look "right".

It's a matter of taste, of course, but I think the S looks great on 16"ers. Definitely don't care for the look of 18" on the S2k, but again, that's ME.

s2kdriver80

Thanks for the replies.

Yea, even if the larger wheels (I mean the 17s, I think 18s are pushing it) provide minimal or no benefit, at least they'll improve the look of the car if you choose your wheels right. I personally think that 17s are the perfect size for the S2000 in terms of looks.

I guess the main reason why upscale sports cars have large wheels is to accommodate the large brakes? Even then, do the brakes fill up the *entire* space behind the wheel? They're probably trying to balance performance, aesthetics, and the perception of extravagance.