I actually got 423 miles on one tank - wow

[StuntDriver06]

Originally Posted by LAfirefytr

How do you correct for tire size when computing MPG? I just went from 245/75/17 to 325/60/18 and of course my MPG has taken a HUGE hit. I'm just curious about how you correct for tire size and if maybe the way I'm calculating now (I divide the number of miles on my trip meter by how many gallons it takes to refill truck) needs to be adjusted somehow because of the new tire size?

ok, if this is on your titan the stock size tires are 32.7 inches.... the new size for yours is 33.35 (325/60R18) so divide new size by stock size and get 1.01... so take that number and multiply it by your trip meter reading and use it for milage..... so if it was 300 miles read on dash * 1.0198776758409785932721712538226 you get 305.96 which is basically 306 miles.... not much of a difference..... however, if you had 245/75R17's and were using the milage from that then it would be a bigger difference.. so if you drove 300 miles on the 245 17's you should have calculated for 288 miles.... i hope i explained it clear enough....

[Advocate07]

^^Smarty pants.. :P