[Isaac Zachary]

What weather do you have? Would water injection be a possibility? (At least during summer months?)

The EPA has really cracked down on diesel tuners recently. So finding kits that change the tune for any reason can be hard unless it's an EPA approved kit.

EGR delete would help fuel mileage but increase NOx emissions. One the other hand, a water injection setup would help reduce those NOx emissions again. (Just don't let the EPA know.)

Propane is easier to get and handel and cheaper to set up, but natural gas is safer since it has a higher octane.

Since you already cut fire wood, wood gas also comes to mind.

There's also the home manufacturing of nearly free bio diesel.

The main thing that helped me get good mileage in the diesel I had was to floor it and keep the gears as high as possible without lugging the engine. Pulse and gliding helped considerably.