<P> Before the use of diesel engines became widespread, petrol engines were used in buses, lorries (trucks) and a few railway locomotives . Examples: </P> <Ul> <Li> Bedford OB bus </Li> <Li> Bedford M series lorry </Li> <Li> GE 57 - ton gas - electric boxcab locomotive </Li> </Ul> <Li> Bedford OB bus </Li> <Li> Bedford M series lorry </Li>

The petrol engine works on the principle of