A 245/45/16 tires gives OD of about 24.6" (Example Yoko ES 100)
A 245/50/16 tires gives OD of about 25.8" (Example Yoko ES 100)

I believe these measurement valid when they are mounted on 8" width rim. Which gives them normal profile.

Now the question is,
Would the 245/50/16 mounted on 9.5" width rim results in smaller OD?
Perhaps down to about 25" or less

 

I bet the difference would be much less than .8". With the far majority of tires I bet you don't measure a difference at all.

 

The problem is with 25.8" OD. it will rub the fender. 24.6 on 9.5" width rim is okay.

So I am hoping that stretching the sidewall will make the OD smaller. Is this correct?

 

It does but I don't think it's going to be getting stretched enough to make any real difference in circumference. You're talking about losing roughly an inch in diameter and you'd have to stetch it so far it would be ridiculous. I don't think a 9.5" rim will get it done, and even if it did I would not recommend stretching a tire that much.

Why bother with a 245 on a 9.5 inch wheel anyway???

 

25.8" will probably fit in the back, but it won't fit in the front.

What is your dilemma? Maybe we can help you come up with more ideas for resolving it.

-Max

 

You could stay with the suggested rim width, then shave the tire...

 

I have 16x9.5" rim on the back with about +44 offset. As you can see in photo below, if fits fine without rubbing to the fender lip in hard turns. The tire mounted is 245/45/16.

With 245/50/16, it will be about 0.8" taller OD, or 0.4" taller on top. My fear is it will catch the lip during corners.
So having the tire mounted on the 16x9.5", would it actually be 0.4" taller or just 0.1/0.2" taller on top.

artowar: I have this rim currently, and are autocrossing with it. I am not going with suggested rim width of 8". I am wanting to know if I could make it work.
Pricewise, 245/50/16 is cheaper than 245/45/16 too.

Reza

 

Hmmm, if it was me, I'd roll the fender lip. I suppose you could check the clearance by mounting one of the bigger tires, puting the back of the car up on stands and articulating the suspension from full droop to full compression.

If you don't end up with a comfortable clearance, then you can try another tire in the same size, shave the tires, or roll the fenders.

Of course, you can always shave the tires yourself with a few smoky burnouts

 

I doubt it will. The camber gain in the suspension will pull the top of the tire further and further away from the lip as the suspension goes into compression. I'd roll the lip for extra insurance though.

 

It doubt it will rub. I run a 10" +42 with a 275... you're fine.