largest wheels, rims for 2008 Fit LX
 

My *new* used 08 Fit LX comes with 14" rims, 175 65 14 tires. I want to put on wider, 15" rims and tires. None of the local dealerships or tire stores will tell me what is the largest size I can go to.

I know I can go to 15", but how wide? How wide rims, and what size widest tires. Thanks much.