I currently have an 1994 4Runner with a 3.0l V6, automatic transmission, and 32x11.5 tires. My problem is my gas milage. I am currently getting around 9-10 mpg. When I first got my truck I was getting around 15-16 mpg. It ws sitting for about 6 months being driven occasionally, but now it is my daily driver. I replaced the air filter recently which brought my gas milage from 8 to 9-10 which is where I am curently. Any ideas to improve my milage, or any reasons I am getting such bad milage would be great.

 

O2 sensor may have given up, tuneup, throttle body may need to be cleaned. Timing check.

 

SeaFoam spark plugs and wires, smaller tires

 

Have you checked for engine codes yet?

 

i'd definately bet 02, but a full tuneup would definately help. The tires wont help, but you should be able to do better than 10, and i would expect with a tuneup to be able to get 16/17 mixed driving atleast

 

full tune up and seafoam.. .a must after sitting that long...

did the truck used to have 32's on it? If not there is 3% more fuel mileage, not much but a piece of the puzzle.

 

oh good thing to note is that since the tires are off the spedo is off, and threrfor the odometer is off, so the mpg's are innacurate (but still pretty terrible)

 

check compression, if you had a leaky headgasket and it sat, they cylinder walls will pit and you'll lose a lot of compression - happend to my '91.

You should be getting about 165psi on each cylinder.