gearing change
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Freshman User
Joined: Dec 2006
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gearing change
ok, i have a 95 f-150 with a 351 and 4wd and i think it has 3.55 gears. it feels awful gutless to me and i was thinking about changing the gearing from 3.55 to 4.10. so i guess i have two main questions
a) is this going to make any noticeable differance or should i go lower?
and b) is it going to totaly kill my mileage if i do this? im getting roughly 12-17 right now and would like to stay above 12. am i just gunna have to take the trade off? thanks for any help!
a) is this going to make any noticeable differance or should i go lower?
and b) is it going to totaly kill my mileage if i do this? im getting roughly 12-17 right now and would like to stay above 12. am i just gunna have to take the trade off? thanks for any help!
Post Fiend
Joined: Jul 2006
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Tire size is going to be a big factor here. If you are running a very large tire, the gear change will be less effective than if you are running a shorter tire.
I like 4.10 gears for tires right around 33, ,up to 35 inches, and 4.56's for tires 35 to 37 inches, 37 to 39's get 4.88's and 40's to 42's would get 5.13's and 44" + trucks would see 5.38's or greater.
This a general rule of thumb deal for me, as every combo has exceptions. Vehicle weight, use, and engine size all, have to be considered for gear applications, but these work pretty close for me.
As far as your mileage goes, driving style, and highway use will be the biggest factors here. If you see an equal amount of street, and highway use, I would expect the mileage to drop a little but not too much. If you see more street use than highway use, you can expect very good results. The lower gear will help the truck accelerate easily making stop and go easier on the truck, and possibly improving mileage on the street. While the highway rpms will be higher, the trucks ability to overcome hills, and passing, might mean that the mileage may not decrease that much. While I would not have expectations of increased overall mileage, I would not think you would see a dramatic decrease either.
I like 4.10 gears for tires right around 33, ,up to 35 inches, and 4.56's for tires 35 to 37 inches, 37 to 39's get 4.88's and 40's to 42's would get 5.13's and 44" + trucks would see 5.38's or greater.
This a general rule of thumb deal for me, as every combo has exceptions. Vehicle weight, use, and engine size all, have to be considered for gear applications, but these work pretty close for me.
As far as your mileage goes, driving style, and highway use will be the biggest factors here. If you see an equal amount of street, and highway use, I would expect the mileage to drop a little but not too much. If you see more street use than highway use, you can expect very good results. The lower gear will help the truck accelerate easily making stop and go easier on the truck, and possibly improving mileage on the street. While the highway rpms will be higher, the trucks ability to overcome hills, and passing, might mean that the mileage may not decrease that much. While I would not have expectations of increased overall mileage, I would not think you would see a dramatic decrease either.
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Freshman User
Joined: Dec 2006
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well i knew it would drop it a little, but i just wanted to be sure that it wouldnt go down the toilet. so if i was to do this gearing change, where could i go to find the stuff i need? i would have a shop do it, but i have found its cheaper to order the parts and just have the shop install them than to have a shop do the whole thing.
