Im thinking about putting new gears in the rear axle on my ranger sometime in the somewhat near future to get rid of some of the play in the drivetrain (if not most of it), and was wondering what 4.11's would do to my gas mileage. I currently have 3.73 rear end, and 26" tall tires. According to some internet calculators, going from 3.73 to 4.11 will raise my rpms about 300 in 5th. I'd like to make my 4 cyl quicker, but I really dont want my gas mileage to drop much. Right now, im averaging about 22mpg, of course thats with a lead foot, and none of it is interstate. One time I actually got around 26 and that was about 50/50 city/highway......but no interstate. Practically all my driving is on the highway with a 55mph speed limit. I guess I could drive around without using 5th gear for a tank to see what happens......So what do you think?

 

Well your truck will accelerate much easier, I found myself keeping my foot off the pedal and staying in lower RPMs and accelerating just as quick. My gas mileage went up for that. However with 225/70/15s I spun them to easily so now I have my new rims and tires. On the freeway my RPMs were up higher so I tried to avoid the freeway. However I got 20mpg with my 4.0 staying below 2 grand and my truck felt peppy.

 

you have tires smaller then stock, so your stock gears are now to high for a stock setup

and then you want to go even higher?

you will be killing your gas mileage even more, but yes it will give you more pickup, but your top speed to be less

 

you mean low right?

 

I never saw my gas mileage go down when I changed tires. Yea, going to 4.11s would actually make around 4.30 gears, but the rpms will only increase by about 300.......which would make it about 2500rpms at around 55-60 mph......as far as top speed goes, I could still reach the speed limiter. Right now, at 93mph (speed limiter) in 4th gear, the rpms are about 4600.

 

I have 31's with 4.10's and its pretty much perfect for me. I'd say stay with the 3.73's. Your milage would go up for city but drop for highway.