Tire Size for 7.5 Wheel
 

What's the max size for 7.5 wheel? I have 225 but I want to get wider.

why would u want to go with a wider tire?
225 for 7.5 should be just right

Because I bought a non-staggered wheels for my IS250 RWD. How about 235?

You should be able to find a manufacturers chart to tell you what it can fit?

your contact patch of tire is not dependent on the width of the tire ....

better to get 225 to be safe

Care to explain the contact patch? Would it help if I tell you that it's Volk LE37 with size 18x7.5?

wheel does not matter

The larger the load on the tire, the larger the contact patch.
The larger the inflation pressure, the smaller the contact patch.

width has no effect on the contact patch

http://www.tirerack.com/tires/tirete....jsp?techid=10

http://www.tirerack.com/images/tires.../35_series.gifhttp://www.tirerack.com/images/tires.../70_series.gif

Sorry, I'm not 100% understand about that but I get the point. After did some research, I found some people even run 245 on 7.5 width wheels (245/45/17 on 17x7.5). They do it and use it for daily driving and auto-x.

225 is the most common size but is it safe if I install 235/40/18 tires for the rears?

235 ought to be safe. It's on the larger side, but should be fine.

Be aware that a 245 on a michelin might not be the same width as a 245 on a toyo or yoko.

I have several sets of wheels and tires stacked in my garage, and not all the 275s are the same width, even though they are mounted on the same size rims.

235 is fine for a 7.5" rim. 245 is pushing it. 255 would definately be too much.