I have a 91 3.1 Firebird.I'd like to get 17 X 8 rims with wider tires.The stock rim size is 15 and the tire size is 215/65.If I upgrade to the 17 incher rims,do I have to upgrade the gearing ratio or anything? Can I keep the same tires as I do now on the new rims? I'm not too knowledgible about tires/rims so If someone could help I'd apprieciate it.

Edit-Fbodymotorsports says the rims are a DIRECT BOLT ON for any 82-92 Firebird,but will my tires fit?

 

In order to avoid problems with the speedometer and odometer, you have to match the outside diameter of your new tires to the tires that came STOCK on you car. The 215/65-15 tires have a 26.0" diameter. As long as the tires for you new 17" wheels have the same outside diameter, they will not affect the speedometer.

Typical tires that would fit on a 17x8" rim are 255/45-17 (26.0" diameter), 235/50-17 (26.3" diameter), 245/45-17 (25.7" diameter) and 225/50-17 (25.9" diameter). The 255/45-17 would cause no speedo error... the others would result in less than 1% error, which is acceptable.

You can not reuse your 215/65-15 tires on 17" rims. The tire size must be the same as the rim size. You have to buy new 17" tires in one of the sizes I mentioned above.

The "215" part is the overall width of the tire (8.46").... a "225" would be a little less than 1/2" wider than your current tire, a "235" would be about 3/4" wider, a "245" is more than 1" wider, and a "255" would be about 1.5" wider than your current tire.

To verify that the wheels will actually fit on your car, they should have a bolt pattern of 5 lugs on a 4.75" circle. Then you need to verify that the wheel has the correct "offset" to fit correctly within the wheel well. The 3rd Gen F-Bodies have some "mixed" offset requirements on some models, so you need to verify the wheels have the correct offset for your specific model.

 

Thanks for all your help man!