Deciding on 4x4 based on mpg
 

So I'm looking into buying either an older pickup or a 1st gen 4runner. I had a 94 4Runner with a 3.0 and I got real sick of how sluggish and inefficient it was. I'm not big on rock crawling but I live on a dirt road in Flagstaff so snow and mud require 4x4. Since I do a lot of highway driving too I'm looking for the most fuel efficient body/engine combo. I know wheels/tires and engine maintenance will have a big effect on mpg, but what should my target vehicle be? Are regular cab trucks noticeably more efficient than extra cab? 22RE vs 22R?

What mileage were you getting with your 3.0? I average 18-20 highway which isn't bad for an older 4x4 IMO. I will 100% not argue the sluggishness, god damn I wish it had a little more pep especially over passes out here.

22R-E, manual, MANUAL LOCKING HUB

Yup!
I just got 23mpg combined city/highway daily driving mine.

How deep is your mud and snow? You might be better off with a unibody/crossover AWD SUV like a Subaru Forester or Outback. Much better mileage, better highway manners, and they handle well on snow. But if you have seriously deep mud/snow, then the higher clearance of the 4runner/pickup platform will be better.