Sometime down the road I wanna put a 6inch lift and 33-35 tires on. Its a 2wd, 5.4 and has the 3.55 limited slip axle. Do you think a gear change would be necessary? What happens happens when you do change the numbers and what is lost/gained. I am mainly looking to keep good mpg. I think my model gets 15 mpg city, and 18 hw, is there anyway to keep close to that?

 

if you want to keep you gas mileage, get 4.10's with 35's. With 33's I would keep the gears and get a programmer. With 35's, i would go to a 4.10. By installing larger tires, you increase the load on the drivetrain and the engine and tranny work harder.

Think of it this way, your truck is "tuned"(geared) from the factory to offer one of three things. Power, MPG's, or Both. With Power you get acceleration and good mpg around town, but higher rpms and worse mpgs on the highway. With MPG's you get decent acceleration, and lower but adequate rpms on the highway thus offering good mpgs. Both, would obviously be a balance between decent city and highway rpms acceleration and mpgs. Most trucks come from the factory this way. an exception is a F-450 with a massive 4.88 rear and diesel. Obviously that truck is designed for one thing.....power!

Did that rant make sense?

 

Thanks alot! Yes I understand now.

One more thing, would going to 4.10 or any higher actually decrease the strain/wear/tear on my tranny with larger tires?

 

you won't keep 15/18 mpg with 35's and a 6in lift. no matter what gears you put in.

but if you do go with 35's i would put in 4:56's

this set-up is about the same total ratio as most of these trucks came out with the 3:73 gears and 265 tires stock.

By the way i if i baby it i can get 12.5 mpg. you should get a little better since you are 2wd

 

FYI the higher the number 4.10 - 4.56 etc the lower the gear ratio.

so yes a lower gear ratio will decrease the wear tean on the tranny.

 

That must suck getting only 12.5 babying it. I dont have gears in mine and am getting 14. weird.

 

with a 6" lift and 35's? maybe the 04+ years just get better gas mileage.

not sure.

yea i have gotten as low as 9.8. luckily i don't have to drive it if i don't wanto to.

I wonder how low the MPG's will go when i get the 38's

 

efuehrin- You are right. Honestly I would go with 4.56's with 35's. I have 4.88's with 35's and love it!!!!!!!!!!!

But Kane sounded concerned about gas mileage. So with 35's,
4.10's for gas mileage,
4.56's for fun,
4.88's if you want to have ALOT OF FUN and are planning for big ole honkin tires.

 

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