Get 4.88's.

I get better corrected mileage with my 33's and 5.29's than with 31's and 4.56's. I say this not so that you get 4.56's, but to reflect that my regearing made a great deal of performance and positive mileage difference.

Taco's don't have 3.0's.

A person ought to regear once. If you have more money than that, send it to me. I think that 4.88's would be a practical limit for 33's and maybe 35's on your rig with a 3.4 and auto.

I have Precision Gears, they are near the best if not the best itself. Yukon are good as well. I did all my gear dealing through Drivetrain Direct. They get a big thumbs up from me.

 

This is confusing b/c I got the 4.30's with 32's b/c it would put me very close to the factory specs of 3.90's with the factory 28.4" tires. But my gas mileage only got worse, it went from 18 with the 32's and 3.90's to 15-16 with the 32's and 4.30's. Also, my speedometer is still off 10%!

 

I'm guessing it's reading low? Are you factoring in that difference when you calculate your mileage?

 

Yes and yes. It reads 72 mph, but the GPS shows 79, and the bad gas mileage is after adjusting for the incorrect odo and speedo.

 

You would have been pretty much bang on stock with 4.56. Thank you for proving my point, a higher gear ratio (4.3 instead of 4.56) forces the engine to work harder thereby hurting gas mileage.



So in other words this is a general guide of what you want:

28-29" 3.9 or 4.1
31" 4.3
32" 4.56
33-34" 4.88
35"+ 5.29

With an auto you can usually get away with one ratio higher (numerically lower). Don't even bother with the 5.71, it's too weak for anything more than a show truck.

 

Shane...how would you rate my 3.58 gears w/ 31" tires, 5-speed, and the 2.7L...?

Yup, sucks ARSE!

Eventually I will switch to 4.56 so I can run 33's comfortably.

Also, a little bit of personal experience...
My wife's 4Runner w/ 3.0L, auto-tranny, edit: w/ 4.88s, and 31's doesn't have as much pep as my truck (specs above).

Jim

 

I have found my 2.7 has more pep than any V6 I have driven or owned. Now that I have 4.88s it seems to have even more pep, the snap your head back kind....I know, I know, i'm going very far very fast though.

 

With a 5-speed...right?

I think the tranny is where most of the power (or perceived power) is lost.

Jim

 

Yes. And now I go through them, all 5-speeds, before I hit the next light Once I put the 33s on I should be able to get on the freeway in 4th gear

 

Yeah, that 5th gear has always been a mystery to me.

Right now I occasionally have to pop it in 3rd to keep speed up hills (while going 70-75mph).

Re-gearing is definitely on my list.

Jim

 

Are you gonna get a locker at the same time?

EDIT: going to bigger tires hurt my gas mileage. With 4.10s and 4.30s my mileage with 32s is about 1-2 mpg (odo adjusted) worse than with 31s. End EDIT

 

Usually but not always - I've got the Tundra and when I went to 33" tires I went up to 4:56 from 3:91 and my gas mileage stayed the same and my performance went up a notch from stock. I'm now running 35's and did an sas and I've lost 2 mpg overall and my road performance is back to stock or a tad lower. I really should have 4:88's for the 35's for better road performance as the cruise control kicks out real easy on very mild grades.

 

Just to reiterate, I have better mileage than stock with 33's and 5.29's since apparently the engine is in a happier power band.

Joe, glad to see a post back. The rig is looking great, how is it working?

 

I edited out my sweeping generalization. Thanks for keeping us honest.

 

Flygtenstein, what kinda of gas milage do you get with your 33"s and 5.29 ratio. I ask becuz I am about to get 5.29s for my 33"s and possible future 35" tires. I have my 33" baha claws with stock ratio for the time being and my 4Runner is just chugging gas. I cant wait for it to improve with the new gears (and so does my wallet).

 

The Tundra is working great - I haven't been able to run many trails since the swap but the little I did in Farmington and Moab it performed well. The lower proving grounds in Moab was no problem and I busted the right warn hub somewhere on that trail but I finished it on three wheels and it acted like I had all 4 pulling so I was pleased with that. I haven't been out since I had the crawler installed but that should help a bunch. The steering feels a little loose but so far no problems with it. I'll go with a hi-steer next spring and that will solve that little annoyance.