Mineral oil cannot be used as fuel for a diesel engine; it can only function as a lubricating oil. Mineral oil is not readily combustible and does not burn at a fast enough rate to act as fuel. However, vegetable oil does function as an alternative fuel source for diesel engines, but even it can severely damage the engine according to Journey to Forever, an environmental nonprofit organization involved in rural development.
Mineral oil is a naturally occurring oil and effectively coats and lubricates diesel and petrol engine parts. Manufacturers refine mineral oil to maximize its longevity in the engine. However, mineral oil is not highly flammable and cannot keep your engine's pistons pumping.
According to "Car Bibles." oil manufacturers use additives and stabilizing agents in synthetic oil to make it last longer than natural mineral oil. These additives can increase the flammability of the oil and may power a diesel engine. However, these oils are likely to cause significant damage if used constantly.
Diesel engines can burn some oils and other substances as fuel because of their compression ignition. Diesel engines compress hot air to ignite fuel, rather than using spark plugs like in a petrol engine. The air temperature in the chamber is 1,022 degrees Fahrenheit when fuel enters. This temperature can vaporize many substances including vegetable oil and fats. However, mineral oil does not burn quickly enough to keep the engine going.
