Sacramento is the capital of the U.S. state of California and the county seat of Sacramento County. Located along the Sacramento River and just south of the American River's confluence in California's expansive Central Valley, it is the seventh-largest city in California, with a 2007 estimated population of 475,743. Sacramento is the core cultural and economic center of its four-county metropolitan area (El Dorado, Placer, Sacramento, and Yolo counties) with a combined population of 2,136,604. The Sacramento Metropolitan Area is the largest in the Central Valley, and is the fourth-largest in California, behind the Greater Los Angeles Area, the San Francisco Bay Area, and the San Diego area. Greater Sacramento has been cited as one of the five "most livable" regions in America in 2004, and the city was cited by Time magazine as America's most integrated in 2002. Sacramento became a city due to the efforts of John Sutter, a Swiss immigrant, and James W. Marshall. Sacramento grew faster due to the protection of Sutter's Fort, which was established by Sutter in 1839. During the California Gold Rush, Sacramento was a major distribution point, a commercial and agricultural center, and a terminus for wagon trains, stagecoaches, riverboats, the telegraph, the Pony Express, and the First Transcontinental Railroad. California State University, Sacramento, more commonly known as Sacramento State or Sac State, is the major local university. It is one of the twenty-three campuses of the California State University system. In addition, the University of California, Davis is located in nearby Davis, just west of the capital.

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.