paxj92 said:I have an 91 xj w/31x10.50's. I am trying to figure out what kind of gas milage am getting. How much do the tires throw off my odometer?
igotanxj said:you can look up the revolutions per mile of your tires on tirerack, then do some simple division to find out the difference in percentage.
My tires have 11% more revolutions per mile, therefore i multiply my mileage by 1.11 to get the real mileage.
All y'all who say the adjustment from stock to 31 is the ratio he will be pff are wrong. The stock tires are almost always under actual mileage/speed. Somewhere around a 29 or 30 (it varies, including variance in actual tire diameter) is where you'll find the odometer is actually correct.89xj said:or to get a rough estimate using your head, going from a 28" tire to a 31" tire is a difference of 3" which is roughy a 10% inrease in size
or to get a rough estimate using your head, going from a 28" tire to a 31" tire is a difference of 3" which is roughy a 10% inrease in size
igotanxj said:The problem is, tires arent always the size they say they are. A 31 can be 30 or 32 inches, a 28 can be 27 or 29 inches. Plus, you can't do it that way with metric sizing. This way its more accurate, and could be the difference between your odo telling you 15mpg instead of 13 mpg.
Yucca-Man said:All y'all who say the adjustment from stock to 31 is the ratio he will be pff are wrong. The stock tires are almost always under actual mileage/speed. Somewhere around a 29 or 30 (it varies, including variance in actual tire diameter) is where you'll find the odometer is actually correct.
Jim www.yuccaman.com