MPG After Lift and 32's

[98Chilkoot]

I was curious about what fuel consumption I can expect after 32's. I realize that the gear ratio is raise but so is wieght and bulk is increased as well. I would expect probably highway would be better then city, i'm more intressed in what kinda MPG is on the highway. Also any idea on how much the odometer/speedo is off.

 

Thanks Rob Rez

[XPLORx4]

What size tires do you have now? Divide your new tire diameter by the old tire diameter to calculate the percent change:

 

new tire diameter / old tire diameter = % error of speedometer.

 

So if your truck has 31" tires now and you install 32" tires, that's 32/31 or a 3.2% error. At 75 mph (speedo reading) you would actually be traveling at 75 x 1.032 = 77.4mph. At 35 you'd be traveling at 36.12mph

 

This approach is rather simplistic, since actual tire diameters vary by make, model, and even tire pressure, but it's close enough.

 

As for fuel economy differences, again that depends on the tire itself. Going from a 31" mud tire to a 32" highway-biased tire will yield entirely different numbers than a 31" highway tire to a 32" mud tire.