While diesel engines may be common to even the most amateur motoring fan, there is a conspiracy theory behind its inventor that is less well known.
The diesel engine involves a piston compressing air to a very high pressure and a high temperature. Its roots go back to 1893 and German inventor Rudolph Diesel.
Diesel was motivated by a humanitarian vision of his highly efficient engine allowing small independent craftsmen to take on the large industries which had virtually monopolised the expensive, fuel-wasting power source at the time, the steam engine.
Diesel expected his invention would be powered by vegetable oils such as hemp and seed oils. At the 1900 World's Fair in Paris, he ran his engines on peanut oil. By then he was a millionaire and his engines were used to power boats, electric and water plants, cars, lorries and ships.
He died mysteriously in 1913 on a steamer crossing the English Channel. Conspiracy theorists believe he was assassinated by the German government, which was preparing for war. Diesel's friendship with many British counterparts would not have helped.
Within a few years, the petroleum companies had monopolised the market for cheap fuel. It was largely forgotten that diesel engines could be powered on just about anything.