diff gearing/fuel milage

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Jan 18, 2011 | 05:08 PM

036.0stroke

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diff gearing/fuel milage

hey i was wondering what gears my truck has in it. at 80mph im at 2600 rpm at 70mph im at 2200 rpm. i get about 14 mpg all the time. its a 6.0 5r100 cc lb dually 4x4. how many mpg do you guys get

Jan 18, 2011 | 05:18 PM

catman52987

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From: Midway Ky

the people i have heard running that particular set up usually have 4.10's. I have 3.73's in a cc long bed and if i run 65 on interstate empty i get 20 ... in town about 15 and if i hook my hay trailer up it drops to 10. when im on interstate 70 is about 2000 rpm's and 80 is 2200.

edit ... btw those are hand calculated numbers ... not the lie-o-meter

Jan 19, 2011 | 10:27 AM

036.0stroke

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alright thanks. i always hand calculate mine too. from full all the way up the filler neck

Jan 19, 2011 | 11:26 AM

Kert0307

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From: Iowa

Look around the drivers door. There should be a sticker there that has paint code, axle ratio, ect

Write down the two digit axle code and do a search and find what you have.

Jan 19, 2011 | 01:13 PM

adambomb

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that's a good place to look. i think also you can look on the rear diff and there will be a small metal tag printed with a number like 3 or 4. but i would be pretty sure that you have 4.10 gears unless you have a tow boss truck with 4.30's but by your speed and RPM it doesn't seem that way.

Jan 19, 2011 | 03:44 PM

rdunagan

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From: Kerrville, Tx

i have a 06 f350 dually i have 4:10 gears. i run the same that you do. fuel mileage i havent done hand calc. but lie o meter says 13 on highway and 11 in town. but before i put new stock sticks in i got about 16 on highway according to lie o meter. still searching for my loss in mileage problem but hope this helps