on my rear wheels? they are the stock chrome ones

 

its something like X/50/16

 

I run 275/40/17...I think some guys even run 295 with no problems.

 

Stock chrome rims? How wide are those? 8"? I think you can run a 245, but I'm not 100% sure what the rim width is.

 

With an 8 inch wide rim you can run up to 255. Any higher and you need wider rims.

 

drumr, that's not always true. here's a 275/50/16 tire on stock rims:

 

Yes you can fit a 275 on there but you lose the proportions of the diameter of the tire. That would initially have to be a 275/35/16 to keep the proportions right. And after you bring the profile down that much, I don't think the tire would fit on an 8" wheel. Your best bet is a 255/45/16. I have 245/50/16's on my car and they're pretty wide as it is. Good luck