Right now I run on Michelin P235/70 R15s........I want to get some 31's in the future. What I want to know is, how can I tell how big my tire is right now? Am I running on a 29 or 30 right now? The help is greatly appreciated.

Thanks

235/70/15 is listed as a 28" tire thru the metric conversion on www.4lo.com. going with a 31x10.50x15 will change your speedo some but should fit fine and look great.

What do you mean it will change my 'speedo'?

Thanks

What do you mean it will change my 'speedo'?

When you change tire sizes to a size that has a larger or smaller diameter, it affects the reading of your speedometer. Smaller tires will spin faster, larger tires will spin slower. Your speedometer reads the rate at which the wheel turns. Your speedo could show you running either faster or slower than you actually are.

If you go from a 235x75 r15 tire (around 28" tall) to a 31" tire (which is actually only 30.5" tall depending on the brand) you will be increasing the tire size by about 9%.. That means your speedo will read about 9% high..

~Mark

So does this mean that if my speedo says I am going 50 M.P.H., I am really only going like 45. Or is it the other way around?

Thanks

What Gimp said.. I don't know why I said it would read 9% high.. I should have said 9% low.. must have been late in the day..

~Mark