Will 456 gears help MPG?

[nosaj]

I have a 06 F250 with 8" lift 20's on 38's. It still has factory gears with a programmer, cold air, and exhaust. Will changing the gears help me out on mpg. Maybe to 456's or something like that, and if so what are some good brand gears to get?

[RescueF250]

If your gonna do anything you need to do 4.30's which probably will help your mileage thats what I have but havent been on a long trip yet to know. If you tow alot then 4.56 is your best bet on the highway it wont like it much for fuel. Deffinitly pull harder though.

[swamp_ratt]

in all reality, a 4.88 gear is what is optimum for a 38 inch tire. a set of 4.56s would put you fairly well if you dont need a lot of low end towing or mudding power. would be great for highway

[Raul@Stealth Automotive]

i would put 4.30's but i should prob be asking what you do mostly with your truck? if you never tow with it and you want your RPMs to be lower on the highway then go 4.30"s

if you tow heavy with it (over 10klbs) i would do 4.56

-Raul

[nosaj]

Originally Posted by Raul@Stealth Automotive

i would put 4.30's but i should prob be asking what you do mostly with your truck? if you never tow with it and you want your RPMs to be lower on the highway then go 4.30"s

if you tow heavy with it (over 10klbs) i would do 4.56

-Raul

Sad part is, I have never towed with it, in the 8 months I have had it. I haven't bought a hitch for it yet so have just been using my Z71 for lil stuff around the house. But it is there if I ever need it to pull my car or what not. I drive it more around town than anything. Stopping and going constantly. I occasionally go to the next town or so which is about 20 minutes away or the other way is about 45 mins. away. I know it needs gears but don't know what to go with. I want a lil both out of it. I want to be able to hit the hwy if I need to.

[charlie101]

I had Genuine's in my last truck. They're not the best gear out there but they have a no questions asked free replacement.

[RescueF250]

Originally Posted by swamp_ratt

in all reality, a 4.88 gear is what is optimum for a 38 inch tire. a set of 4.56s would put you fairly well if you dont need a lot of low end towing or mudding power. would be great for highway

False 4.88 is not a good choice at all. In a gas motor yes 4.88 is good but not a diesel. There has been many discussion with gears in a diesel, diesel are completely different when it comes to gearing, ask any diesel vendor that does gears and you see. 4.56's are that great on the highway you'll be in a higher rpm range, my 4.30's put me at about 2k at times on the highway.

4.10 - 35 - 37
4.30 - 37-38
4.56 -38 to 40

[PGreenSVT]

Originally Posted by RescueF250

False 4.88 is not a good choice at all. In a gas motor yes 4.88 is good but not a diesel. There has been many discussion with gears in a diesel, diesel are completely different when it comes to gearing, ask any diesel vendor that does gears and you see. 4.56's are that great on the highway you'll be in a higher rpm range, my 4.30's put me at about 2k at times on the highway.

4.10 - 35 - 37
4.30 - 37-38
4.56 -38 to 40

I have to agree with this.

[swamp_ratt]

Originally Posted by RescueF250

False 4.88 is not a good choice at all. In a gas motor yes 4.88 is good but not a diesel. There has been many discussion with gears in a diesel, diesel are completely different when it comes to gearing, ask any diesel vendor that does gears and you see. 4.56's are that great on the highway you'll be in a higher rpm range, my 4.30's put me at about 2k at times on the highway.

4.10 - 35 - 37
4.30 - 37-38
4.56 -38 to 40

hmm... ive had all the big 3 (stroker, duramax, and cummins) with 38s and 4.88s and they all ran great at 75mph er so. just my personal experience

[swamp_ratt]

ya know i got ta thinkin... i had the 4.88s in my mudder diesels. my bad. although i did have 1 97 stroker with 4.88s and 38s, but that was a few years back. dont remember what that one ran.