This is a bit discouraging to read. I too have a '92 4Runner 4WD ATM 3.0 V6, stock everything. I'm getting around 12-13 mpg. I was thinking (hoping?) it should be in the 16 mpg range, but it looks like a lot of people are getting similar results. I still need to replace the O2 sensors to see if they make a difference. They are originals (145k miles), but they are not throwing any codes. Replaced spark plugs and cables, air filter, tranny flush, new muffler. No real difference in observed mileage. I love my 4runner except for the mpg and the poor power. Damn you 3VZ-E! My dad's Suburban gets better mileage

 

funpow, I'd almost guarantee you'll see an improvement with a new O2 sensor. Max lifespan is about 90k kilometers... less miles! And they tend to fail gradually ie you will see mileage get closer and closer to garbage before it ever throws a code (if it even does ever throw a code!)

Change it, use a Denso replacement, and I think you'll be a bit happier.

 

Sadly the governmant rates for a 3.0 automatic 1992 4Runner are 12 city and 15 highway. But they show in their feedback that some drivers get 19. You can look up any car here:

http://www.fueleconomy.gov/feg/Power...WD&srchtyp=ymm

My 2000 automatic 3.4 4Runner is getting 22 mpg consistantly which is above what gov't promises.

 

how much in-town driving you do vs highway? My auto always got 17-20mpg with mostly highway speed driving, get into town, stop & go etc, 10-13mpg...

That being said... doing mostly highway speed driving, I got an avg of 17 mpg.

May also replace the o2 sensor as stated above, as well as checking the tps, vafm, coolant temp sensor etc...

 

That's almost all highway and I use the cruise control. I pretty much drive only 5-7 mph above speed limit. I don't really drive in heavy traffic conditions hence the cruise control. I had a tuneup with new plugs, wires etc. about 10k ago.

It's weird the difference in mileage rating between the 2nd and 3rd gens. I have an '89 too, a 1st gen 4Runner. It only has 149k but with an exhaust leak it gets terrible mileage. It has a 22RE, 5 speed, but only gets about 11 mpg.