Caterpillar engines can burn a wide range of fuels. The most preferred by Caterpillar though are distillate fuels. Diesel fuel is a petroleum-derived compound which is heavier then gasoline but lighter then lube oil. The fuel is injected into the compressed, high temperature air of the combustion chamber where it ignites spontaneously.
Fuel is rated by the cetane number of the fuel instead of the octane in gasoline. The cetane number refers to the ignition quality and the cleanliness of the fuel. It depends on the application of the equipment to determine the fuel that you should run though your caterpillar. Cat