I did not realize the V6 Dakota's might drink that much fuel. I thought those trucks typically got closer to 20 mpg. It sounds like the mileage can vary considerably.

My D150 only got 10 mpg on the one tank I checked. That tank was used for mostly short trips with plenty of starting, stopping and some idling time. Often the choke probably never even opened. I was not expecting it to be very good. It's a typical 318 / automatic truck with 2.94 gears. It escaped from the factory without the "lean burn" system or the lock-up torque converter. When it is driven on longer trips it will hopefully use a little less fuel. Obviously, it will never be an economy vehicle.

The D and W series trucks I've driven have typically been 3/4 ton, 4x4's that got 10-12 mpg. The EPA rates my current truck at either 12 or 14 mpg. I have not found what made the difference in the rating. Perhaps it was the axle ratio, but it could depend on whether or not the truck had the "lean burn" system. The 2.71(?) axle ratio was standard. The 2.94 and 3.21 ratios were optional.