donberry

early 81, recommended tire is 225/60 15. I have searched many sites and have not seen anything about using 235 tires...
1. Can I use 235 on the same wheels the 225 are on
2. any advantage...

seems to me a little more tire on the road......?


I am going to order some tires and was just wondering if I should consider the 235.........

David Floyd

Just make sure the outside diameter is the same or your speedo will be off a little.

SharkSkin

Depends on your rim width. If the tire is wider than the rim, it will have more tendency to roll under(or in extreme cases, off!) in hard cornering.

D

Garth S

Yes, 235's will fit your 7" rim width; however, is there anything to be gained? - depends on the specific tire. Just for fun, I checked Michelin and BFG tires in 225/60 and 235/60R15: The 'H' rated Mich dimensions vary by little more than 0.1", wheras the BFG shows 0.4" (the full 10mm) in both section (235mm), and height. So you need to check the tables of the specific tire(s).
As to gain, if the full section gain of 10mm is available, the tire then has a proportionatly higher sidewall, ie. - 60%, or 6mm higher. Probably a bit more comfort, not a lot in performance: the performance gains are mostly reserved for lower aspect (50 series) tires... then that means 16" wheels and so on.
Without checking further, I'd guess there is a greater selection available in 225/60R15 (than 235's) that will 'feel' right on the 928.

Jim bailey - 928 International

Porsche recommended 215 x 60 x 15 for the 7 x 15 rims for the comfort ride ........ I run 225 x 50 x 15 Kuhmo victor racers on the very brown 1980 but they are a bit short ....which I really like . Taller sidewalls while giving a softer ride will also deform more under hard cornering and too wide a tire for the rim width is in my opinion very unstable . With a 235x60 the tire diameter is about 3/4 inch " taller " .

Randy V

Verify that the overall rolling diameter is the same:

Tire Size Calculator

donberry

well after talking to the tire guy, I ended up ordering the Yoko ES100 in the size recommended by Porsche - 215/60/15.
Thanks for all of the info .......
now ... to tell the wife I bought some tires