2002 Tacoma 4x4 Awful Gas Mileage

I bought a 2002 Tacoma 4WD last March and ever since I got the truck, my fuel mileage has been terrible. Its a 30 mile drive one way to work, and I’m eating almost a quarter tank of gas from there and back home. I get my oil changed at the recommended time with synthetic oil, change fluids when needed and always make sure the tires are at the right PSI. Not really sure what else to do, but with a part time job I’m hardly able to keep up with refueling every 3-4 days. I’m thinking its intake/ exhaust related? Brakes were rubbing on one caliper at one point but I replaced the pads and calipers on the front two wheels, but it hasn’t helped. Thoughts?

 

What gas milage are you getting?

 

Averaging about 10-11 right now. Thats not too bad, but i'm hoping theres some ways to improve it. It was supposed to get around 16 from the factory from what Ive read, but taking into account the daily wear and tear of 17 years of driving I would assume it would drop a few mpg’s.

 

Most first gen stock V6 Tacos in decent shape should get close to 15 mpg, right?
Are you stock tires, no lift, etc?

 

I always got 18-20 mpg with 2" lift and 265/75R16 Duratrac tires on my old 2001 V6. Had 290k on the clock when I replaced it, too.

 

Yeah it should be much better than that. 200k on mine, and I have a hard time getting it below 20. But its small, and a 4 cyl.

 

Thats about what i got in my 02 when i had it. I didnt have a lift but i did have some decent all terrains.

 

When’s the last time it was aligned?

 

is this 30 mile one way on a highway or in heavy traffic?

10-11 mpg is not good!

what psi are you tires set at?

 

Its about 25 miles of highway and 5 miles of traffic, however the gear ratios on the 4x4 Tacos are atrocious, which could explain a little bit of it, but cruising 65 it shouldnt be burning as much fuel. The truck has only been driven 120k miles as of now.

 

have you changed the fuel filter or know if its been replaced ever?
not sure if that would make any difference or not

 

It has a leveling kit and im running all terrains that are factory size. Ive had other trucks with similar lifts and tires and I didnt notice a difference, maybe 1 mpg. But this truck is just eating through gas like crazy.

 

The receipt says it was changed at about 105k miles, 18 months ago. Ive pulled it out and checked it once already and it had no buildup or trash in it.

 

Alignment? plugs, wires? Air filter?

 

Yeah, that is pretty dismal fuel economy. It must be costing you a small fortune in fuel!

Another rock to consider looking under would be your O2 sensor...
The primary oxygen sensor might be on its way out and reading improperly. This can cause a dramatic decrease in fuel economy. Something worth considering.

 

Is the check engine light on? There's lots of ways to get bad gas milage, but an engine code might help point in the right direction.

 

Is it throwing a lean code? Sounds to me like you’re running lean. Intakes on these crack, MAF and Throttle Body could need cleaning, when did you get spark plugs last? Mine needed whole new coils. Start at the intake and work your way through. Should be able to troubleshoot something. Engine code would help if anything is throwing.

 

Start with basics. Get a full tune up done on it, clean the throttle body and MAF sensor, plugs/wires, air filter, etc.

If you have a check engine light on then that needs to be addressed first and foremost. Even if you don't, with 11mpg I would scan the ECU anyway just to be sure. Maybe the CEL bulb is burned out or the previous owner removed it.

Is your truck stock? Stock tires, no lift, armor, etc?

 

Do the cheap fix and clean the MAF with some sensor clean. See if that makes a difference. Then move on to the fuel advance, ive heard they can slip. Then check the valve clearances, as its never been done on most of those engines since factory.

At some point you can check that your o2 sensors are still within voltage spec. I say check those last, but between the MAF and the o2 sensors, replacing both o2 sensors will cost the most. And chances are they are rusted into the exhaust so good luck getting them our if they're broke.

Oh and your cat could be plugged and not throwing a code. Good luck.

 

If your only using “almost” a quarter tank for 60 miles of driving you should be getting more than 11mpg. I average about 14mpg and I get around 50 miles for a quarter tank. However my truck is not stock and it’s heavy.