loots06

This can't be right! I few months ago I had 20sput on and I saw my MPG drop like a rock.My MPG dropped from 22 to about 12 in the city. On the highway it went from 24.6 to 17. Can some please explain to me why the exterme variation. I was expecting a drop maybe 1-2 MPG but not nearly half. I have onlydriven the car about 200 milessince I put on the new wheels/tires on. Does the fact that they are staggered have anything to with this? I think not and cant seem to find a reasonable explanation.I have tried the reset but that did not work.

howarmat

what are the sizes of the new wheel combo

Nuke

Did you recalibrate your speedometer for the change in revs per mile?

Briscoe

You shouldn't be losing MPG because of 20's, I went from 34's to 37's on my truck and lifted it 6 inches and I lost about 20% on my MPG. If you have the same circumfrence on your tires you should not notice any difference.



18 MPG down to 14 MPG on my superduty.

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06Redfire3V

Yea 22 to 12 MPG just cuz of having 20's is not correct at all.

Devil Wolf

sweet jebus i wish i got 22 mpg. im at a soild 15.1.

my first mustang

Did you reset your tuner for the different revs per mile of the 20s??? I'ld be willing to bet this is your problem.

4LITER6

here an interesting question, if you are running staggard, and the the revs per mile on the rear are different from the fronts, is anything compromised?

howarmat

some of you i think are missing the point....being staggered or going to 20s in not a problem at all.....you can do that and still keep the stock diameter (27.1) and it only matters what the rear wheel is as far as i know.

laserred02

Is this the mileage from the trip computer or hand calculated? As others have noted if you have not updated the computer to compensate for the diameter change your speedo and other things will be off contributing to erroneous MPG calculations by your computer.