I would like to get a bigger footprint without buying new wheels. how wide can I go on the stock 17's. I was also thinking of using spacers to bring them out more..maybe 20mm. At this point, I am not lowering, but I may go 1" lower in the future.

 

i wouldnt go any larger than 225/45 on the stock 17x7

 

I was thinking maybe 225-50 to get better gearing and fill out the wheel wells a little more.

 

225/50 will work but you're putting more sidewall on the car, thus larger tires, thus heavier tires. gearing might be better but you'll still be slower acceleration wise and your speedometer will be off.

 

FYI, 225/45R17's are the largest guaranteed rub free / trouble free fitment for O.E. wheels our fitment team recommends!

 

What would the performance difference be between 225 & 215? I know the 225 might have a bit more contact patch, but also might not have the turn-in response of the 215. Considering these and other potential trade-offs, which size do you feel would perform better on the stock wheels, 215 or 225? (Yes, both same brand/model/aspect ratio)

 

I wouldn't mess with spacers, as they can be troublesome in the near future. It might work for a while, but once you think everything is going well for ya it will start screwing other parts up. Just from personal experiences.