Does anybody know about running diesel engines on straight vegetable oil?
Depends on the age of the engine / type of injection system if this is acceptable. An older indirect injection engine will run fine – may need an occasional dose of injector cleaner or an occasional tankful of high-quality normal diesel fuel (with detergents) just to keep everything clean, but should otherwise be fine. However newer engines with higher-pressure direct injection systems, especially those with either common-rail or pumpe-duse injection systems won’t work quite so well. The lubricity of the vegetable oil may not be enough to keep the high-pressure pumps properly lubricated. Also, the smaller nozzles in the injectors are more likely to get gummed-up with the oil. In cold weather starting the engine will be difficult or even impossible, as the vegetable oil’s viscosity increases significantly as its temperature falls (put a small amount in the fridge to see what happens). Normal diesel fuel has additives to prevent this (most suppliers actually use different fuel formulatio
