88alltrac

Ok here is the deal. My 4runner has a rebuilt 22re with about 8k miles on it now. 5 speed. Runs like a top. I am running 31x10.5 tires with the stock 4.10 gears. I pretty consistently get about 17 mpg in town which I am satisfied with. On the highway the best I have seen is about 14mpg. This seems too low to me.
I know my gearing is wrong with the tires. Do you think switching to 4.56's will bring my highway gas mileage up a bit?
5th gear rpms are a bit too low on the highway and 4th gear rpms are too high.
I hear lots of people getting low 20's with their 22re's.

coryc85

Hmm, something doesn't seem right. I can't believe your mileage goes down on the highway. Are you accounting for the lower odometer reading because of your larger tires? Seems like you are since 17 city driving is good. My 4Runner on 33" tires and 4.88s is getting 17 in mixed driving. Are you running the AC, or are your windows open?

With your stock gearing and 31" tires, 5th gear should be giving you 2645 RPMS at 70MPH. 4th gear will be 3111 RPMs.

If you go to 4.56 gears, at 70 MPH, 5th gear = 2941 RPMs and 4th gear = 3461 RPMs.

So I don't see how your highway mileage will improve with the gears.

88alltrac

i think the 4.56's will improve my mpg because it brings the rpm's up a little. under 3k is too low for these engines. in 5th gear i have to give it gas all the time to keep going that speed where if the rpm's where up i would not have to give it as much gas.
most of my driving on the interstate is windows up and no A/C

if i drive in 4th gear on the highway my mileage actually comes up a little bit. i just dont remember how much.
i want to get her at about 32-3300 rpm's at 75mph, which is what i drive.

i would probably just live with it and keep her in 4th except that i already have a 4.56 rear 3rd from another vehicle and so i would only need to track down one for the front.

kawasakimoto_7

i have the same problem, i have 31's and 4.10's on my pickup and i get worse mileage on the freeway.. and i drive at like 65 mph AC does increase the RPM's a little too by the way.. just if you didnt know alltrac

87AzRunner

idk about your freeway mpgs but I do know that stock
your truck came with 28" tires and it now has 31" tires.

so the odometer most importantly was not geared for it.

pretty much to come up with your true mileage divide 3/28

the 3 is for the 3in difference in your tire size from factory,
you should come up with a decimal .107143 which you then
multiple by miles traveled on your trip counter (sr5 :] ) or
odometer get some number like 19 or 17 if you traveled like
200 miles, add it to your total miles traveled then divide by
gallons filled into tank to top off

pretty much in my truck (4.30 with 31 tires) for every 11 miles i
travel there is about a mile that did not register on the trip meter
because of the odometer factory calibrations.

88alltrac

i have checked my mpg with gps. i know the odometer is off.
i guess i had pretty much decided to go to 4.56 a while ago. i have the rear diff i just need to find a front one for cheap.