It only costs my time as I am using palm seeds as the feedstock, and gathering used cooking oil. My other project is gasification of old tires, or biomass to produce gasoline. As long as I have a source for free waste I can drive. For long trips I can either seek out local restaurants or use the wood powered van with waste wood. But I have older cars so their engines are very forgiving. Most of my trips are within 40 miles of my home so I can fill my tank with my backyard pump.

Antique? It's new to me.