London

London is the capital and largest urban area of England and the United Kingdom. An important settlement for two millennia, London's history goes back to its founding by the Romans. Since its settlement, London has been part of many movements and phenomena throughout history, including the English Renaissance, the Industrial Revolution, and the Gothic Revival. The city's core, the ancient City of London, still retains its limited medieval boundaries; but since at least the 19th century the name "London" has also referred to the whole metropolis that has developed around it. Today the bulk of this conurbation forms the London region of England and the Greater London administrative area, with its own elected mayor and assembly. London is one of the world's leading business, financial and cultural centres, and its influence in politics, education, entertainment, media, fashion and the arts contribute to its status as a major global city. London boasts four World Heritage Sites: The Palace of Westminster, Westminster Abbey and St. Margaret's Church; the Tower of London; the historic settlement of Greenwich; and the Royal Botanic Gardens, Kew. The city is a major tourist destination both for domestic and overseas visitors. London's population draws from a wide range of peoples, cultures, and religions, and over 300 languages are spoken within the city. As of 2006, it had an official population of 7,512,400 within the boundaries of Greater London and is the most populous municipality in the European Union. As of 2001, the Greater London Urban Area had a population of 8,278,251 and the metropolitan area is estimated to have a total population of between 12 and 14 million.

Gasoline Engines

Gasoline engines have the advantage over diesel in being lighter and able to work at higher rotational speeds and they are the usual choice for fitting in high-performance sports cars. Continuous development of gasoline engines for over a hundred years has produced improvements in efficiency and reduced pollution. The carburetor was used on nearly all road car engines until the 1980s but it was long realized better control of the fuel/air mixture could be achieved with fuel injection. Indirect fuel injection was first used in aircraft engines from 1909, in racing car engines from the 1930s, and road cars from the late 1950s.

Gasoline Direct Injection (GDI) is now starting to appear in production vehicles such as the 2007 BMW MINI. Exhaust gases are also cleaned up by fitting a catalytic converter into the exhaust system. Clean air legislation in many of the car industries most important markets has made both catalysts and fuel injection virtually universal fittings. Most modern gasoline engines are also capable of running with up to 15% ethanol mixed into the gasoline - older vehicles may have seals and hoses that can be harmed by ethanol. With a small amount of redesign, gasoline-powered vehicles can run on ethanol concentrations as high as 85%. 100% ethanol is used in some parts of the world (such as Brazil), but vehicles must be started on pure gasoline and switched over to ethanol once the engine is running. Most gasoline engines cars can also run on LPG with the addition of an LPG tank for fuel storage and carburetion modifications to add an LPG mixer. LPG produces fewer toxic emissions and is a popular fuel for fork lift trucks that have to operate inside buildings.