Troubleshooting Ford Ranger

[cjb900]

I bought a truck about a week ago. Its a 2000 Ford Ranger Super Cab with a 4.0 v6. Automatic transmission. It is a 4x4 but I only drive it in 2wd. It is lifted and has 32 inch tires. So far I have put new tires on it. The other ones were shot. I have also changed the oil to Mobile 1 high mileage synthetic and have used one small bottle of fuel system cleaner. It came with a cold air intake and dual exhaust. Pipes aren't very big on it though. It has been very cold outside.

I am going to commute to college this semester about an hour away. Unfortunately I have class five days a week. I wanted to only have to go MWF or T TH, but that didn't work out.

Heres the deal. I am getting awful mileage. I calculated about 14 mpg. I would say most of it was highway driving, and I baby the throttle. I know it is a truck but I would expect a little better mileage. It is kind of a small truck after all. I plan on making a HHO dry cell and making some small changes/maintenance to squeeze out a little better mileage. But is something possibly wrong with the vehicle? What are some things I should check that would possibly be bringing down my mpg?