MPG tire. Do they make a difference?

So right now i am getting 10mpg and running 32's with 3.55's in my 89.

Will putting the stock 205's back on will it increase my gas mileage enough to make a difference?

I just don't want my junk to look ghetto with stock tires and a 4" lift.

thanks'

-PJ-

If you had 205's and you went to 33's and didn't recalibrate your speedo gear then your mileage numbers are off by as much as 20% as is your speedometer reading.

I had 225's (stock), I went to 31's the difference was 10% without recalibrating (new speedo gear) Example: 1 mile on the highway mile markers = .9 mile on my odometer or 100 miles = 90 miles, So if my Jeep is getting 250 miles per tank on the odometer it's actually pulling 275 miles. Math comes in handy.

I'm running 31's and 4.10 gears in my 91 XJ and get about 19mpg on the highway.

When I went from the stock 215's to LT235's my mileage corrected itself, my odometer was dead on, it was off running the stock tires. I wonder if jeep did that on purpose to make you run thru the warranty faster....

The type of tread definitely can and will affect MPG, tire size also has a factor as well. an 11.5 wide tire will definitely have an affect on mileage. But by not adjusting your speedo that is the biggest error.

Johnnie Walker said:

The type of tread definitely can and will affect MPG, tire size also has a factor as well. an 11.5 wide tire will definitely have an affect on mileage. But by not adjusting your speedo that is the biggest error.

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The wider tire will affect mileage, yes, (through drag and weight) but only the circumference of the tire will affect the reading.