Long before there was any need for a motor insurance quote, people mostly got around by either riding a horse or walking. Then in the second half of the 19^th Century two German engineers came along.

Wheels may well be over 5000 years old, but the cars we drive around in only made their debut in 1885. German engineer Karl Benz fastened a small petrol engine to a three wheeled cart and made the first, if somewhat primitive, petrol powered car. He was following in the footsteps of another German engineer, Nikolaus Otto. Otto had actually invented the petrol engine in the first place, about twenty years earlier. It shows what a stroke of genius Otto had when inventing the engine, because almost all car engines designed since have embraced his four stroke principle.

In layman’s terms, a car is a metal box which has wheels at the four corners that takes a person from A to B. In scientific terms, a car would be described as an energy converter i.e. a machine that releases the energy locked inside a fuel such as petrol or diesel and then turns it into mechanical energy which moves wheels and gears. When the wheels power the car, the mechanical energy then becomes kinetic energy. Cars are powered by fuels made from petroleum which is the thick, black, energy-rich liquid. Petroleum is buried deep under the ground and during the 20^th century it was the world’s most important source of energy.

A car engine is built around a set of cylinders, there can be anything from two to twelve cylinders, but normally four, six, or eight can be found inside. The cylinders are made out of an extra strong metal and then sealed shut, but at one end they open and close much like a bicycle pump. Inside they have tight fitting pistons that slide up and down inside. At the top of each of the cylinders, there are two valves that can be opened and closed very quickly. The inlet valve will allow fuel and air to enter the cylinder from a carburettor, while the outlet valve allows the exhaust gases to escape. At the top of the cylinder, there is also a spark plug; this is an electrically controlled device that will make a spark which will set fire to the fuel. At the bottom of the cylinder, a piston is attached to an axle which is constantly turning; the axle is called a crankshaft. It is the crankshaft that powers the gearbox of the car which, in turn, drives the wheels.

There’s no doubt that Otto’s petrol engine was an invention of genius, but it is now a victim of its own success. We have over 500 million cars on the planet, the pollution produced by this many vehicles is a serious problem which is likely to get worse before it will get better. The carbon dioxide released when the fuel is burned is also a major cause of global warming. The solution could well be electric cars, as they get their energy from cleaner sources of power or even a hybrid car that will use a combination of electricity and gasoline power.