Myth: You Can Use Vegetable Oil as Diesel Fuel
This myth has a legendary status among “off-grid” enthusiasts who claim you can run your truck on leftover fryer grease. If you own an old, mechanical diesel tractor or a Mercedes from the 1970s, you might actually get away with it. Those older engines were simple and robust enough to burn almost anything. However, attempting this in a modern “Common Rail” diesel engine is a recipe for a multi-thousand-dollar repair bill.
Vegetable oil is far more viscous (thicker) than standard diesel. Modern fuel injectors operate at incredibly high pressures and have microscopic openings that will instantly clog if you use thick oil. Unless the oil is chemically converted into “biodiesel” or the vehicle is fitted with an expensive two-tank heating system, keep the cooking oil in the kitchen.
