I'm having trouble deciding on a wheel for my car. I've narrowed it down to either 15" or 16" and I'll probably get either a Rota Attack or C8. Here's my dilemma:

I prefer the look of the 16" over 15". However, the 15's are considerably lighter while the 16's offer a larger contact patch for greater traction. Which is more important, a few less pounds or larger contact patch? Any experienced advice would be appreciated.

I am aware of rotational mass and how it affects acceleration. Currently I'm running stock drivetrain but plan on swapping to a B series in the near future. Yes, I know that will move me up to a more difficult class for autoxing, but I can live with that.

 

Normally people will go with the smallest wheel they can and choose tires after that just to avoid raising their final drive ratio for autocross. For track events, you may or maynot want the rollout to change depending on top speed concerns, but for autocross you will generally benefit the most from being able to accelerate turn-to-turn as quickly as you can manage, and a smaller wheel/tire combo will help that.

BTW, how wide are you looking to go? There's plenty of 15X7 wheels out...

 

a smaller diameter wheel helps acceleration (vice versa with a larger one)...a smaller diameter wheel also weighs less

for an autox only tire you'll ideally want the rare 13" x 8" or 14" x 8" as the ideal wheels for your car...faster turn in, better braking and faster acceleration will improve your times

as for the c8 15" x 6.5" they are decent rims...i have them on my 2k1 civic sedan and they have definitely helped braking/acceraleration/cornering over the 15" x 6" steelies with oem firestone squealers

 

They are good but unfortunately don't come 7" wide ATM. However, I've herad some whispers of 7 inchers from Rota. We'll just have to wait.