I have a 94 YJ 4.0L 5 speed with 31x10.5x15. I would like to find out my MPG. I got 213 miles on what I think is a full tank. (my gauge is messed up, said it was on empty but would only take 11gal) I know my speed is off so I'm guessing that my mileage would be off too. (I hope its becouse 14.2 MPG would suck) Can someone tell me the math or about what my mileage would be?
if your speedometer is off your readings will be off. gps is a good substitute. if you have one that records miles and top speed and all. you start by filling tank to top and reset trip meter on gps. then just go and drive. next fill up fill to top like before and look at the mileage you recorded. Take your trip mileage and divide by gallons needed to refill. that will give you mgp.
Those mile markers on the highway are a good way to tell how much your speedo is off. Drive about 20 miles and compare your odo to the highway markers. My xj is off by 8% due to larger than stock tires. I take the mileage, multiply by 1.08 and divide by the gallons used.
99 XJ Sport
3" Skyjacker lift
31 x 10.50 General Grabbers
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