bad gas milage

[tri856]

right now im averaging about 11-12mpg. im driving around 30 miles a day and out of the 30 miles 10 of those miles are city. im not sure if thats average or somethings wrong with the bigger tires and wheels? im driving regular no towing, just to school and back im not racing or not of that i just drive my truck from point a to point b and back

[Keliko]

Same truck but 2004 v6 xe cc in my case complete stock with 31's on stock rims. I average about 17 mpg. I wonder if mine is going to get that bad when I do get around to doing my 3" sl.

[Hertz]

I have steel wheels and 32s also. And a 3 inch suspension lift. When calculating the average for a tank of gas it usually comes out between 14.5 and 16. Overall average, I would make a guess of 15.5. I never calculated in the difference in tire size because my speedometer is not off that bad (2 mph at 65) and I didn't think it would make that big of a difference. After all my "32s" are not really 32 inches tall, none of the imperial sized tires are, so that 1.15 number is not right anyway. You'd have to physically measure your tire if you wanted it to be exact.

[jerryp58]

Don't underestimate what looks to be a small difference. I didn't look up the original tire size for a v6 for my year. In my case (according to Tirerack.com specs), my 225/70-15 Generals were around 27" and my 235/75-15 Kumhos were around 29" (just working from memory right now). I remember when checking on the exact sizes they showed, I was running about 1.05 larger tires. It can make a difference. In my case, I average roughly 25 mpg unadjusted. 25 * 1.05 = 26.25 Not too big a deal, but 1mpg is 1mpg (or 1.25 in this case). For some of you who may be running 33 vice 31, you could be looking at the same type of correction. You're likely already taking a hit in aerodynamics and overall tire/rim weight, no point in adding an error. My $0.02 or $0.021 if I use the correction.