Gasoline is not as easy to ignite as you would imagine

Gasoline is an oil product that most people know from personal experience. But: many people do not think about what exactly they are buying at the gasoline pump. Most of the time, the customer does not even see the product!

Gasoline an ordinary, clear and almost colourless liquid

To the naked eye, gasoline is an ordinary, clear, almost colourless liquid. This is only appearance; gasoline is a complex mixture of different hydrocarbons and not prepared from just one oil fraction, but carefully blended from many different refinery product streams.

The gasoline engine operates on a mixture of air and vapourised gasoline. Therefore, sufficient evaporation of gasoline under all circumstances is essential. This requirement sets limits to the so called boiling (or: distillation) range and vapour pressure (VP) of a gasoline.

Gasoline is not as easy to ignite as you would imagine

An ideal gasoline, contrary to popular belief, is difficult to ignite. Ignition should take place exclusively by the spark at the spark plug, but not spontaneously by compression in the combustion chamber (pre-ignition). Next to pre-ignition another combustion aspect can be observed called: knock. Knock is the knocking or pinging of the engine after the mixture has been ignited by the spark plug in the normal way.