Tire size/ Gas mileage

[trueblue00]

I was running Goodyear Lt 245/75 r16 tires on my 00 F150 I just changed them out and I am now running Firestone 265/75 r16 on my truck . The goodyears were all season the Firestones are MT. Since I have put the bigger tires on I am losing about 120 miles to a tank. Does that amount sound right. I was getting about 340 now I am getting about 220. Could it be something else? Any imput would be great.

[unclebubbles]

Originally Posted by trueblue00

I was running Goodyear Lt 245/75 r16 tires on my 00 F150 I just changed them out and I am now running Firestone 265/75 r16 on my truck . The goodyears were all season the Firestones are MT. Since I have put the bigger tires on I am losing about 120 miles to a tank. Does that amount sound right. I was getting about 340 now I am getting about 220. Could it be something else? Any imput would be great.

The larger tires will cause the speedometer and odometer to be inaccurate in proportion with the difference in circumfrence. Depending on the year model, you may be able to have the pcm flashed to correct this. Once you get it corrected, you may actually get better mileage, because it increases your overall final drive ratio! Good luck.
Later
Ed
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