Tripmeter-odometer wrong-better mpg

[charlie]

Hi,I bellyached here a while back about my 2001 Tundra V-8 showing 2000 rpms at 60mph,when every other v-8 reads 1900 rpms.I also noticed that my Tacoma(sold a while back)odometer read 1497 miles on a trip from New Orleans to Flagstaff AZ.The Tundra read 1450 miles on the same route one year later.My Accord reads 95 on the same trip the Tundra reads 91.9.
Well,I finally did the obvious.I zeroed the tripmeter at a milepost and drove 50 mileposts.My Tundra tripmeter showed 48.2 on the 50 mile trip.I did this twice(no,I was actually going somewhere,I am not that compulsive).It works out to traveling 3.7% further than the odometer reads.Anyone else have this problem?It does mean my actual gas mpg is about .5-.6 mpg better than I though.I am getting 17.7 instead of 17.1 at 70mph,and 14.5 instead of 14 in the city.Seems small,but the city mileage bugged me(16.4 at 75 mph bugged me also,it is actually 17,a friendler #).I wonder if my truck"thinks" it has 245/70 16 tires on it rather than the 265/70 it came with?Some Tundras come with 245/70's.
Anyone else notice this?I have the stock tires on it 265/70 BFG.
Thanks,Charlie

Moderators Noye: The thread " Tripmeter-odometer wrong-better mpg" has been moved to the Tires & Wheels Forum for better exposure and replies. PM was sent to the thread starter of its relocation. --- Possum

[SATundra]

Heres an older thread on this: Larger tire = false milage readings

Basically the Tundra is calibrated using the 245 "stock size" tires.

[openspaces]

On hte same note I am looking to go plus one size in tires. I have the stock 265/70 and am going to get one of the larger tires on when these wear out. Am I under any obligation to calibrate the odometer?