What petrol is? Definition by Wikipedia
Gasoline "???s?li?n", also known as petrol "?p?tr?l" outside North America, is a transparent, petroleum-derived liquid that is used primarily as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives.
On average, a 42-gallon barrel of crude oil (159 L) yields about 19 US gallons (72 L) of gasoline when processed in an oil refinery, though this can and does vary based on the crude oil source's assay.
The characteristic of a particular gasoline blend to resist igniting too early (which causes knocking and reduces efficiency in reciprocating engines) is measured by its octane rating. Gasoline is produced in several grades of octane rating. Tetraethyllead and other lead compounds are no longer used in most areas to regulate and increase octane-rating, but many other additives are put into gasoline to improve its chemical stability, control corrosiveness and provide fuel system 'cleaning,' and determine performance characteristics under intended use. Sometimes, gasoline also contains ethanol as an alternative fuel, for economic or environmental reasons.
Check the condition of the car in auto-service
The possibility of buying a used car makes even the less wealthy can enjoy the benefits of this mode of transport. Just remember that buying a used car requires the driver to have a good knowledge of cars that will be needed for this, that has not been cheated. Therefore it is worth, before signing a contract to buy a car ride with him to the site, where you can seek a professional opinion about its condition. A used car can also be cheaper to operate because it will be reduced to its used parts, and buy cheap motor oil. We only need to pay close attention to their quality and not to buy the car parts excessively cheap.
US petrol price fluctuations - Wikipedia
From 1998 to 2004, the price of gasoline fluctuated between $1 and $2 USD per U.S. gallon. After 2004, the price increased until the average gas price reached a high of $4.11 per U.S. gallon in mid-2008, but receded to approximately $2.60 per U.S. gallon by September 2009. More recently, the U.S. experienced an upswing in gas prices through 2011, and by 1 March 2012, the national average was $3.74 per gallon.
In the United States, most consumer goods bear pre-tax prices, but gasoline prices are posted with taxes included. Taxes are added by federal, state, and local governments. As of 2009, the federal tax is 18.4? per gallon for gasoline and 24.4? per gallon for diesel (excluding red diesel). Among states, the highest gasoline tax rates, including the federal taxes as of 2005, are New York (62.9?/gal), Hawaii (60.1?/gal), and California (60?/gal). However, many states' taxes are a percentage and thus vary in amount depending on the cost of the gasoline.
About 9% of all gasoline sold in the US in May 2009 was premium grade, according to the Energy Information Administration. Consumer Reports magazine says, "If (your owner?s manual) says to use regular fuel, do so?there?s no advantage to a higher grade." The Associated Press said premium gas?which is a higher octane and costs more per gallon than regular unleaded?should be used only if the manufacturer says it is "required". Cars with turbocharged engines and high compression ratios often specify premium gas because higher octane fuels reduce the incidence of "knock", or fuel pre-detonation. The price of gas varies during the summer and winter months.