rim size and tire size-what fits? [Archive] - Team Camaro Tech

: rim size and tire size-what fits?


Ken67SSRS
Aug 25th, 00, 12:37 PM
I am trying to decide what size BF Goodrich Radial T/As to order for my rally wheels. I have 15x6 for the front and 15x7 for the rear.

According to the tire chart, a 6" wide rim and fit anything from P195 up to P235 (!!!). I was thinking P215/60R15, but was worried that was pushing the limits (tread width is 7", section width is 8.6").

Is this a safe/good size for this rim? Will steering effort or handling be adversely affected because of the bulging sidewall?

Considering P245/60R15 for the 15x7s on the rear.

Thanks to all!

kz1000ltd
Aug 25th, 00, 03:30 PM
I think you're pretty much on the money. I have 235/60/15 front and 255/60/15 rear on my 15x7 Ralleys, and I believe this is a pretty common combination. You should be fine.......KZ http://www.geocities.com/kz1000ltd/

Ken67SSRS
Aug 25th, 00, 03:43 PM
In case anyone is interested, I found some great information on tires and sizing at http://www.inil.com/users/dlbrown/ofwhl.htm#WHLTires

Scroll down to the sections:
Tire & Wheel Size Considerations, and
Technical Stuff

From the info in Technical Stuff, 215 on a 6" would be way too wide for "maximum lateral grip in the twisties, and best turn-in feel". A 215 width would be best fit to a rim between 7.6" - 8.8" (!) Personally, I think a 215 on an 8" rim would look awful skinny.

In the other section, the guy gives this advice: "Tire tread width about the same as the rim width. Or tire section width about 10 - 15 % wider than the rim"

Ken67SSRS
Aug 25th, 00, 04:04 PM
More from the same page:

Here's my attempt to distill all the information presented so far:

(1) Never exceed the widest wheel rim-width specified by the tire manufacturer. This will usually be between 90% and 100% of the tires section width.
(2) As long as rule (1) is obeyed, the wider the rim, the better the cornering grip. Smoothness of ride may decrease as the rim gets wider, though.
(3) If you already have a specific wheel, mount the narrowest tire that will fit that rim if you want the most cornering grip.


So, if cornering grip were the MOST important thing, and considering the specific tread and section widths of the BF Goodrich Radial T/A, I should consider something more along the lines of:

front 15x7 with 195 / 60R15
rear 15x8 with 225 / 60R15

....uh, I don't think so. http://www.camaros.net/forum/smile.gif