So I'm looking into BFGoodrich's G-Force series, particulairly their G-Force Drag Radial and G-Force KDW. I have stock 17" rims. My questions is, how wide can I go safely on these rims? 245? 255? Anyone know?

 

probably can get 255's on safely

 

Depends on the brand of tire - no two brands' sizes are the same. A friend of mine has a '98 Cobra with the stock 17x8 wheels and he ran 275/40/17 Firestone Firehawk's with no problems. No excessive bulging either. But try that same size tire with a different brand on the same wheel, and you might have problems.

 

That's pretty much it MTAS. 255's will be universally be OK. Depending on the tire manufacturers recommondations you may be able to go to 275's.

My Nitto NT450's for example give a range of rim widths acceptable.

The 275/50's range from 7.5 - 9.5 with 8.5 being optimal The 255/50's from 7.0 - 9.0 with 8.0 being optimal.

When it's time for tires I may give the 275's a try on the rear and see how that goes.

 

I once saw a set of 315/35/17 on a 17x9 Cobra R wheel, and the tires weren't the Nitto DR 315's (which apparently work well on a 9" wheel), and MAN did they bulge! Downright scary looking.

 

When I asked about 315s for the rear wheels at Les Schwab, the salesman there told me that he used 17" tall x 10.5" wide rims on the 315mm rubber, and it fit just fine.