What size tires???

On the stock 17x8's 275's are the MAX wide you should go. To run really wide tires (like 315/35's) you should get at least 10" wide wheels.

Do a search on here for wheels for idea on what sizes to go with.

Also remember that actual tread contact may bet better with the 245's vs. 275's since the 275 will tend to bulde at the sidewall due to the wheel not being wide enough. This cause the tire to "cup" in the middle, so you lose some tread contact that way. I say just stick with stock size tires or get a nice set of wider wheels/tires off ebay or the classifieds. For the $500 you'll spend in tires you can almost have a nicer set of wheels/tires that will look a ton better and have properly sized tires.