Regearing/mpg after lift?

[Rem870xj]

I just joined here and I am looking into lifting my truck in the next couple of months. I am checking everyones set ups out and trying to deside what Im looking for. I originally thought 35" tires were all i wanted but 37 really aren't much more and neither is a bigger lift when it is all said and done. I have delt with jeeps and so on but im not sure on these bigger trucks, do none of you guys regear after a lift on anything around 35 or 37" tires? I am going to look into my axles and find out the ratio. i have a 01 f-250 bone stock xl model with a rear limited slip so i think it may be geared a little lower, I dunno??? If not how bad have a 6" lift and 37" tires done to your gas mileage? and how do these trucks do at highway speeds and towing with a lift??? Thanks for any advice, sorry for all the questions.

 

[Crusin350]

I have 35's and didn't really notice any performance difference. I will say that 35's aren't enough (for me anyway), I will be going to a 6" lift with 37-38's next time. I get a little upset when I see a 1/2 driving around that that is the same size as a 3/4 ton.
back to the gears... I am not an expert but I think I heard that you dont really need to change anything till around 38 inches or maybe even taller.

 

[keanoknick]

I run 38.5" tires, and still have the factory gears which are 3.73's
This last weekend at the drag strip I was able to briefly break all 4 tires loose on one of my launches. These trucks have plenty of power for them, I can cruise up mountain passes at the speed limit or better without downshifting and with the EGT's at a safe temp.
With my Six gun on the Speed Loader (highest) setting I still see about 15.5 MPG doin 70 on the freeway with the cruise control on.
I haven't towed more than about 5k lbs since the lift, but it handled it just fine, and I'm sure it could handle 10-12k.
If you get blocks in the rear, just be sure to get some traction bars, or you'll get bad axle wrap pretty easily.

 

[big_rooster]

only problem i've seen so far without regearing is it takes awhile to get it in overdrive. But by keeping the 3.73's which you prolly have you only run bout 1800 rpm's down teh road so it helps the mileage some.

 

[97powerstroker]

i have a 4inch lift and 35's and 3.55 gears,1st thru fourth gear not much difference,but overdrive is significantly weaker,on my truck anyway,97 psd,its also a 5 speed manul,my next tire size will prolly be 33's,i just dont need my truck way up in the air,for 1,im short,and 2,i dont do any offroading,i might take it to mudfest but 33's are fine.

 

[01Extreme69]

I have got 8" lift 38" tires, with 4:56 gears. Runs great, take some time to get into OD unless I am getting on it. Just be sure to keep your front end lubed up if you are going to run tires 38" and up. Keep an ear for them wheel bearings also. Power is awesome. I can smoke a rice burner all day. Towing, not bad. Carried a 9K lb trailer from VA to IN with no problems. Rides a little bumpy but if you are used to Jeeps you will be fine.


Just remember jack em up, fat chics cant jump!!