After running 5 different 1st gen 4x4 over the past 20 years this is what I have found. All these trucks were/are stock toyota carburetors, 22r engines, stock otherwise with the exception of some have/had 31" tires, and some have/had 235-75-r15's.
better highway mileage, (50-55) mph, 25.15 mpg
average highway mileage (speed and load vary) 21.17 mpg
better around town mileage 18.8 mpg
average around town mileage 15.29 mpg

These are mpg in US gallons, converted from liters per 100 kms.

I have always been aware of my fuel economy, and these results come from roughly 180 000 miles driven.

These trucks always have been, and still are my daily drivers. All are short boxes, but I just acquired my 1st long box, I look forward to fixing it up!

 

My 83 with 35s and 5.29s is getting around 17.5mpg mixed highway town and off road.

1983 pickup, bobbed, new 22r, weber 32/36, 3row radiator, rear Detroit locker, front Spartan locker, 5.29s, 35" km2s, high steer, 350 ignition with Accel racing coil

 

Can't wait to see what mine gets. I've had bad experiences with carbs in the past.

1980, 20R, 4Spd, 2WD.

Though, when I see people pull up next to it in a parking lot and check it out, who cares?

 

I was getting 12MPG with 22R Dual weber 45DCOE15's, Cannon Intake Manifold, no emissions, no vacuum advance on 33's with a 4" lift

 

11-14 mpg but i have a 4.3 chevy with th350 trans toyota case and 4.10 gears

 

I've got a completely stock '80 2wd long bed with a 20R and a 5 speed.

I've only calculated it twice, both times around town, and i'm only getting around 12.. I think my carburetor is crap though. Do Weber's help or hurt the mileage? I'm considering the swap.

 

1982 22R, stock, 14.32 MPG with 31" super swampers, mostly in-town with a couple highway runs. Also have bad carburetor issue. Will report back once rebuilt and also after just changing to some more normal all terrain tires.

 

83 22R, .040 over, 261c cam, weber 38, 4.88., 33" BFG AT, 6500 elevation. Driving on-road, off-road, city, highway 80mph. Having to drive fast with around 75hp...

Avg 17.29.

 

Completely Stock with 20r

highway approx 21mpg

 

Assuming my odometer is correct, I just got 227 miles out of 11.87 gallons, which comes to 19.1mpg. Most was on 215/75R15 snow tires, a little on 235/75R15 brand new Destination AT. Most of it was 15 mile trips to town at ~40mph on bumpy twisty back roads. I have a longbed with a 20R, camper shell, and no relevant mods.

My previous tank was about 14.5mpg, but that included some off/bad-road driving, towing up to 5500# GCW, and more idling than usual.

 

I had switched to some worn-out 31" BFG ATs, and they're so bald I'm measuring 29" diameter, I think. Anyone know for sure what size tire the gearing is made for? I think it's 29".

I got two STA Super Traxion bias-ply, and so far, I love them. The tiny little extra gut busting from them is worth the looks to me. Anyway, I'm running those up front until I can afford 3 more for the rears and spare. We'll see what 4 of them do for the economy, they're nice and narrow at 7" to the BFGs' 10.5". Really deep treads though.

With this tire combination still running BFGs in the back, I'm still at around 14.60 MPG, mostly city. You can't call sitting still on the highway or cruising back roads at 25-45 highway driving, and that's my commute these days. I go through 3/4 tank a week.

I've got a 4 speed, I'll have to scroll through and see how mileage is on 4spd. vs. 5 spd transmisions. My goal is to install a 5spd whenever I end up rebuilding the engine. That's going to be a good little while from now.

PS: The highest I got on my all-highway cross-country trip was about 18mpg, fully loaded down. Not quite as good as my shortbed 2wd, same type of trip, same loadedness. Almost, though.

 

After a few fill-ups, I have been averaging 19-21 MPG on my 1983 4WD Pickup - that figure is already corrected to account for increased tire size over stock. I'm pretty satisfied with the power to efficiency balance on my setup.

Here are the engine/drive train specs for those who don't know already:
*Completely rebuilt original 22R engine (bored 0.020 over)
*Completely desmogged
*Weber 38 DGES
*Trail Gear Rock Ripper stainless headers
*2.25" exhaust with Thrush Welded muffler (no cat)
*Stock 4.10 gears
*31x10.5 Falken Wildpeak A/T tires on 15x8 Ion Style 171 aluminum wheels
*Approximately 3" of total lift via OME springs and longer shackles

 

That's all I get with my 32-36. Now I have carb envy, since I just replaced mine due to my throttle shafts leaking air.

 

On my first tank since desmogging and lifting I got 15.4 MPG (not sure how to calculate for how accurate my odometer is though).

22r w/ 32/36 weber, 35" tires and 5.29 gears

 

One way to get a decent odometer calibration is to reset your trip meter at a mile marker on the highway the next time you take a road trip, or note the odometer reading. The farther you drive, the more accurate the error estimation, so if you get to the 100 mile mark and you are showing 110 miles, you have a 10% positive error. That's about what mine does with LT245/75R16 tires. They are about 31" tall.

This is not really accurate for the speedometer though. You really need a laser to get a quick speed estimate for that. Next time you see one of those stationary laser trailers that flash your speed in red if you go 1mph over the limit, try a few passes to see if 60mph on your speedomoter matches the flashing speed. Always good to know how fast you are REALLY going, in case you pass a State Trooper in the median !

 

1980 Pickup 4x4 (see signature) 12.6mpg. Needs a rejet because elevation is 4100ft here. Gonna do that this weekend. Probably could get a little more in-depth with my timing as well. Those two factors should give me a nice jump.

 

This is my Road Trip app on my iPhone. Only filled up twice since I installed it but the graph will start providing some legit information over time.

 

I have an 80 with 20R/4-Speed. Since I've done my Weber carb conversion I average 16-19.

 

My 83 with 31x10.50 and 3.91 gear if I drive it right got around 17. If I have foot to the floor I got more around 14

 

With 35x12.50 and 3.91 I'm on average getting 13mpg.