[Primitive]

I've been keeping track of my mileage by calculating trip meter and gallons filling up at the pump.
Im doing between 10-13mpg combined.

This Titan was purchased used with 144k, it has these Comforser 285/70/r17 lt mud tires. I measure it and it's around 32" diameter. Aside from that I don't know much else about truck that causes such poor mileage. Any ideas? The suspension is also very soft for some reason, maybe the previous guy fitted some off-road shocks on it.

 

[jdmartin]

City or highway? You're not that far off, especially considering you have mud tires. The biggest effect on fuel economy is your conditions and your foot. If you do all your driving city, you're going to get in the very low teens - no way around it. When I'm using my truck doing short runs for work, I get 14MPG or less. Highway I can get up to about 17 or so but I live in the mountains.

 

[Primitive]

City or highway? You're not that far off, especially considering you have mud tires. The biggest effect on fuel economy is your conditions and your foot. If you do all your driving city, you're going to get in the very low teens - no way around it. When I'm using my truck doing short runs for work, I get 14MPG or less. Highway I can get up to about 17 or so but I live in the mountains.

That's combined, mostly cities. I've now pumped the tires to around 40psi and I can see mpg has increased.

 

[Blackbeauty]

Cracked exhaust manifolds will drop your MPG 1 or 2 MPG on average... Check the condition of yours.

 

[rsoto80]

sounds normal to me

 

[HRTKD]

If you're 4x4 check the u-joints on the front axle shaft. A friend of mine has an '07 Armada with 170K miles on it. When he replaced his u-joints his MPG went way up. With that many miles I would probably be replacing all the u-joints in the drivetrain, not just the front.