Anyone ever put 235/40/19's and 295/35/19's on a 997.1?

(versus 235/35/19's and 295/30/19's)

Rubbing or other issues?

 

Go to www.willtheyfit.com and do a comparison between the front 2 tires and then the rear 2 tires. It will calculate the diameter and speedo difference and you can see if the sizes your looking at effect the front and rear equally. If they're different by more than a little bit, you may have PSM, ABS, and or handling issues. Your speedometer will definitely read low too since your sidewall will now be taller i.e. 40% vs 35% of the 235 section width on the front and 35% vs 30% of the 295 section width on the rear. Since you're dealing with percentages and adding 5% at both ends, but not starting with the same multiplier, they're going to become different relative to one another.

 

Thanks for the link to that site Petza. Very helpful. I acquired these BBS wheels with the tires on them (991 size). The wheels are the same fit for my car, 997.1, as for the 991 but the tires are larger. Tires are in great shape so just wondering if I can mount the tire/wheel combo for now and get new tires later.

according to the site speedo error would be 3.63% front, 4.11% rear. So 0.48% dif.

 

OK, decided not to risk it so I am having new, proper size, PSS's installed as we write. So, I'll have some very nice PSS 235/40/19's and 295/35/19's for sale. Also have a near-perfect set of chrome lobster-fork wheels for sale if anyone is interested.