Help with Tire sizing. Moved from 16 to 17

[pbs911]

I finally ordered my new wheels last weekend and now want to start looking for tires. On my 16" wheels I ran 205x50 front and 225 X45 rear. I want the overall tire height to be the same with the 17" wheels. Can I go to 45 series on the front and 40 series on the rear for the same ride height? I know different manufacutres may vary, but I would like a ballpark idea. The car is my daily driver and will see DE events.

I was also planning to run 205's on the front and 245's on the rear. The wheels are 7.5" front and 9" rears. Sound OK?

I hate to bring up the tire question, but if you have tired tires you would never use again, I would appreciate the imput.

[Bill Verburg]

205/50 & 225/45 all in 16 is an odd combination for a 911. More usual is either 205/55 or 225/50 front which has a dimeter of ~24.9" and 245/45 with a diameter of 24.6" again in 16"

The usual path for a 17" upgrade is to either 215/45(~24.6" tall) or 225/45(~25" tall) for the front and either 255/40(~25.1" tall) or 265/40(~25.3" tall) at the rear

Bigger can be used with proper wheel offset and additional work at lips and trailing arms and oil lines. But unless you have some specific goal in mind I would avoid the larger sizes

All sizes cited above are for Bridgestone SO-3. Other manufacturesr may have different dimensions. Check at Tirerack for specifics.
Here is a link to the SO-3 page;

SO-3 Info

[pbs911]

Thanks Bill. In my haste I forgot about the spec section at Tire rack. It answers all my questions except the bad experieces with tires.