I bought an 01 tacoma 4x4 double cab about 3 weeks ago. I have filled the tank twice so far and both times averaged about 12.5 miles per gallon. The truck has 104000 miles. I have no service records. No owners manual. I'm not to sure what to check or do first.

Make sure your tires are properly inflated to the correct PSI, replace new spark plugs and wires and drop in a new air filter. That should get you at least another 1 MPG better. Next, you can change all your fluids like oil, diff, transfer case, etc. to synthetic.

Don't drive like a maniac, but more like a grandma and pretend there is an egg between your foot and your pedal everytime you drive.

If you do jack-rabbit starts, you're going to kill your fuel economy. If you drive on the highway over 65 mph, you're going to kill your fuel economy. Learn to use the cruise control on the highway (when it is safe to do so) and not change lanes unless you have to. When I drive the speed limit, I can get 300 miles to a tank of gas with about 2 gallons left in the tank. I don't know if you drive an automatic or a standard, but you'll get less fuel economy with an automatic transmission. The double cab also adds a weight to your vehicle so that's going to affect fuel economy.

I drive a standard and like an old man in my '01 Tacoma and I get about 16 mpg locally and 22 mph highway. City traffic is a fuel economy killer and I anticipate red and green lights and coast up to them accordingly. On the highway, I anticipate how traffic moves and I don't gun & brake and tailgate just because I want to go faster when traffic doesn't allow it. I also don't fill up the tank every time I stop for gas. I only put in $30, and I drive only when I need to and that $30 of gas lasts me a week.

Realistically, people don't buy trucks for their fuel economy. If you wanted a truck that gets 30 mph, you're not going to find one.

I have a 2001 4x4 standard cab 2.7L and I am having the same prob. however I do have MT tires on it as well as a cold air intake and throttle body spacer along with full exhaust. And that seemed to make it worse. So I do feel your pain and I am going to play around with some things to see if i can improve my fuel econ. I will keep you up-dated if I figure anything out.

I drive a full size F 150 supercrew 4x4 5.4 and though I had a gas hog,I get 14 city and 16 on the open road.

If your getting 12MPG, then something is wrong. Check all the normal things and give it a full tune up.

Let us know when you find out what is killing your mileage. If you have big tires, that'll do it. Also (in addition to the tune-up suggestions by HUMANOID) what about a possible rear brake drag? Arco (I think it's them with the blue sign and the charge for using a card at the pump - ****) gas seems to suck as well, try a big name and use medium grade on one tank and see what happens. Consider A/C use as well: that zaps my mileage. I get about 18 in town and (when I don't drive too fast) 22 on the highway in my '04.

Oh sorry for that " ******* " but I do avoid that @(#$%^&*)_+ing gas station