Can every diesel engine run on biodiesel without modifications?
It depends on how much biodiesel you use. If you are mixing in 20% biodiesel with your normal diesel (yes, you can do this without any problems) no modifications are required. If your vehicle was made before 1994 it may have natural rubber fuel lines. These fuel lines are not compatible with pure 100% biodiesel, and will need to be changed for Viton lines. This is a relatively easy and cheap fix for most cars.
