My daughter wants her first car to be "green." Can bio-fuels be used with any diesel? Do we have to have modifications made?
Most modern diesel engines can utilize partial biodiesel, usually 2%, 5%, 10%, 20% or other low-percentage bio sources. In colder climates, 100% biodiesel can be too thick for some fuel systems, so if you live in such areas, ask if the biodiesel retailer whether the fuel has additives to prevent thickening. Another option is to mix petro diesel with bio diesel by alternately filling your tank when it is half full of the other type of diesel.
The big question is whether your daughter's engine will support that variety of fuel. There are a few forums devoted to only diesel and bio-diesel, they might be worth checking out.
Any vegetable oil would need to be purified down to a minute level and most likely mixed with diesel before using (again depending on the engine).
Thanks for the information. We thought we could re-use vegetable oil from restaurants -- do we need to buy a bio-fuel from a retailer?