Originally Posted by
pilotmike
risky, not using the proper stuff. Skating on thin ice.
Properly refined, bio jet fuel is nearly indistinguishable from the dead dinosaur-based stuff. While used cooking oil is obviously a very limited supply, there are some very promising carbon-neutral fuels based on oil made from things like algae that can be scalable to supply most if not all aviation needs.
BTW one of the guys I used to play Ultimate Frisbee with drove a VW Diesel powered by used vegetable oil. Rather pleasant smelling exhaust (yes, it did smell a bit like fried potatoes).