I have a 96 taco 4x4 5spd with 32x11.50x15 yoko geolanders
x-fer case is a 2.70 in low range
i get 18.5 mpg consistently with about 50/50 city/highway driving which i feel is pretty good for the 3.4L
and I air down to 20psi when wheeling

I don't do any hardcore rockcrawling/wheeling but have been on some pretty rough trails that dont result in body damage. I dont go too often either, havent been in some time in fact.

Anyways, I always thought I had a 4.10 but today I checked the vin plate and counted driveshaft revs and indeed it is a 3.90. I hear all this talk of going for lower ratios like a 4.56 but I have never felt like I was limited by my setup. Next mods are a winch and ARB locker for the rear. What exactly would I be limited by not going with a lower ratio? I always feel like even the slightest amount of throttle can break the tires loose on dirt or rocky hills so why other than crawl speed would I go lower?

If you dont have any problems driving it on the street and dont plan on going to a larger tire then I wouldnt bother with regearing

3:90 on an auto is the same as a 4:10 on a manual trans correct? so if you have an auto trans then I wouldn't worry about it as scottie said.

"I have a 96 taco 4x4 5spd with 32x11.50x15 yoko geolanders"

3.90 with an auto would be worse, as the autos have a taller overdrive. (.70) or something like that

yeah I just checked on 4x4wire. 4.10s standard for manual transmissions, 4.30s standard for automatic transmissions. but that's for the pickups not the tacos. I am sure the trans on the tacos are geared for the 3.90s though. I think you know what I mean however.

i have a 2000 taco xtra cab 5spd with 3:90's 2.7 and 33x10.50's. its my dd but it does see sand and snow on occasion. it gets 20mpg average. i would like to re-gear just for a lil more mpg and wheel-ability/drive-ability , though i find that its "unnecessary" for my application. . lower gears is also easier on your clutch, though ive had my 33's for over 4yrs and 45k with no problems at all. in fact the clutch still feels like new.

http://www.grimmjeeper.com/gears.html
drop down select R150 for the taco trans and hit calculate to see the ratios.

I am still not convinced that a lower gear will bring back mpg. i guess one would have to look at a fuel flow chart that compared throttle position to rpm

anyhow, if you have some threads that concretely show this then I would be interested.

city mileage would go up and highway mileage will either stay the same or go down slightly. this is because you can send more engine torque to the larger wheels to get them started, but once going on the freeway there will be very little difference if any with how much throttle will be needed to keep turning. But highway rpms will be a little higher hence the possible lower fuel mileage on the highway, but might not even be noticeable.

yeah I just figured for 50/50 driving it would be a wash whereas if you did all city then it would benefit and if all highway it would hurt.

I have an 81 p/u with 3.90 gears pushing 33 13.5 and for now that's fine for the wheeling I do. When I upgrade to 35" tires I will definitely switch to 5.29 gears.