Norm Peterson

Sometimes it's hard to tell where the actual extent of the tread is, and on 10" wide rims you've got a little more lateral support than you would with, say, 9's or 9.5's.

Your rear tire pressure may be a little high - a load index 101 or 102 tire does not need as much air as a 97 load index tire in order to safely support the same corner weight. There is a rough correlation between differences in load index and differences in pressure for the same load rating, but I don't have it handy.

If this picture link works, maybe we can narrow things down a bit.
http://www.amazon.com/gp/product/B00...F5SFJ0GM0ZPDBZ

I will get those section views up, it's just that the only way I can do it is a little clunky and I have to delete a couple of other pictures first.


Norm

Norm Peterson

Here they are. I'm not even going to try to get the shape of the shoulder areas any closer. Not worth it for the usual comparisons.

I used Falken's dimensions for the 20's instead of converting mm to inches. Comparison in both cases is to the OE 235/50-18 on 18 x 8.5.

There's only about 3" between the rim flanges and the ground, and that's with the tire unloaded. Figure you lose a half an inch or a bit more due to tire compression when you drop the car down off of the jacks. The couple of psi extra stiffens the tire, so you don't lose as much and the tire is stiffer and won't compress as easily (which you will feel).

Front . . . has a little more sidewall bulge shape



and the rear




Norm

Norm Peterson

BTW, thanks for prodding me into downloading the FK452 specs.


Norm

Nuke

C'mon, Norm. You know you wanted to. You just needed an... excuse.

Norm Peterson

I was all set to just use dimensions computed from the nominal size, but figured maybe working from the mfr's own numbers would be better here.


Norm