Pictured is some of the best 80's technology <img src="/forums/images/graemlins/lol.gif" alt="" />

On the right 2.6 Liter Solid Metal Beast 17mpg if your lucky
On the left 1.6 liter go-cart 30 mpg if your lucky.

All those "rumors" of 20mpg in a Montero was somewhere in Flatsville with a slight downward grade plus a tailwind <img src="/forums/images/graemlins/wink.gif" alt="" />

...both ways!

My v6 raider in stock form got 20-23 hwy. <img src="/forums/images/graemlins/kewl.gif" alt="" />

I broke 20 in my 93sr.

I have broken 20 in my 91, 15-17 lately.

So just to summarize its going to depend on your location, driving style, how good of upkeep on your vehicle, add-ons/offs, whether the moons are alligned right, etc....
Expect 15-20ish

I got 10 MPG in Victorville with a 40 knot headwind <img src="/forums/images/graemlins/evil.gif" alt="" />

So far, I've been averaging 17 mpg but did get 20mpg once. Since my fuel gauge is broken, I calculate it everytime I fill up and reset my trip. I have the stock 225 tires. The 20 mpg was with more then average highway travel (at 60ish mph in 5th) and I rarely opened the secondaries on that tank. Disconnect your secondary diaphragm and watch the mileage climb! <img src="/forums/images/graemlins/lol.gif" alt="" /> Of course it'll be a real slow climb. <img src="/forums/images/graemlins/nana.gif" alt="" />

One thing to keep in mind when calculating your MPG too is tire size. If you have larger tires, you will show MPG that is higher, as you're recording less miles than you actually drive. Also, if the truck has smaller than factory tires, you would likewise show lower than actual MPG.

For comparison, my company vehicle, a 2006 Nissan XTerra 2WD will get a best of 21 on the highway, and that's if I'm nice. I usually average a combined 19.5. Of course it's much bigger, holds 5 people comfortably, and has a 267HP 4 Liter V6.

Just keep in mind that you're driving something made out of all metal, with a full frame, and it's as aerodynamic as a phone booth.

I used to get over 20mpg on the highway with mine when stock. Now I just fill it up when it's low <img src="/forums/images/graemlins/kewl.gif" alt="" />

I think that's backwards. Bigger tires travel farther across the road for the same RPMs, and hence log less relative miles on the odo.
(At least I hope that's the case. If not, then I'm getting 12MPG with 33s! <img src="/forums/images/graemlins/zombie.gif" alt="" />)

Larger tires show less than actual miles.