Ive debating in my mind whether to get 15 or 16's? what are the pros and cons?

 

The only pro I can see to a 16' wheel is it looks a little better.It isn't going to help your acceleration any.Actually it should slow you down a bit.16" tires cost more .On the good side you can put a wider tire under the car which will help you while cornering, etc.However,If you plan on autocrossing I would buy a set of cheap 15' and R compound tires.

 

16's if you are keeping your stock rims. The only exceptiong is you plan on tracking your car in which 15x7 would help out with larger tires.

 

Track ==> 15" - R compounds are cheaper in this size

Street ==> 16" - go with forged if you can