Can someone tell me how much my odometer is off with the tires I am running. I am running 285/18 instead of the stock 245/17.

 

Just do a yahoo search for axle ratio and many sites with calculators will come up. very easy.

 

This should help out.http://www.xracingsports.com/tirecalc.html

 

We need to know the aspect ratio of the tire. List the full tire sizes and I can tell you.

 

it is amazing how many people do not understand that the first part of the tires size is not the heighth 285 or 315 this is crucial but you need to have the ratio or percent # to tell the heighth.

I was thinking about this today will we ever see an 80sereis tire ie 285/80 17
not so wide like the 315 but still give us some heighth? 285 70 17 were on a truck I saw today and they did not look big enough and they were a mud too. I used to run on my 85 chevy 255 85 16 which was a great size plenty tall but did not stick out bad.

 

The stock tires that came on the truck were 265-70r-17. the tires that are on there now are 275-70r-18.

 

Your odometer will be 4.90% off. So, when you travel 1000 miles, your odometer will show that you have gone only 953 miles. Also, when you are going 70mph, your speedometer will read 66-67 mph. Hope this helps