The Brazilian Copaifera langsdorfii can be tapped (ala maple syrup) for a natural diesel fuel that requires only simple filtering before being poured into a truck. The catch? The diesel only has a shelf-life of about 3 months.
Ranches and farms in areas where the tree grows might well be able to provide most of their diesel fuel. The article says one acre of trees can output 25 barrels per year, which is roughly 1050 gallons. If they can tap it like maple syrup is done now, with long lines of hoses flowing to a central location rather than individual buckets on a tree, then it should be cost-effective too.
This would be similar to what sugar cane plantations in Hawaii are doing, using the leftovers from cane processing to create biofuel to run their tractors and trucks.