The Pontiac Purusit GT 17 inch rim is 6.5" wide...what would be the widest you could run on these rims. think i could go with 215's or even 225's and not have it look stupid??

BTW the stock tire is 205's

 

You need to go to a tire shop and have them look this up. If you know what kind of tire you want pull up the data sheets on the tire manufacture's website. A 225 in a Michelin may mount on it whereas a 225 Bridgestone may not. This is just an example since almost every 225 tire can mount on a 6.5" rim.

 

ive ran 225 on a 15x6 wheel...so on a 15x6.5 u should be able to do a 235 without it looking like its ballooning out

 

The general rule is don't go more than an inch over the wheel width with TREAD WIDTH. This is not the 205 or 215. Those are the section width. Find out what the tread width of the tire is and use that as a judge. Just remember, at an inch over wheel width they will look a little fat.

 

when you buy tires it will tell you what size rim it will fit. like 5-6.5 or 11-15.

 

i think 215 is the widest you can go.... at least that was what bridgestone told me.....