From 1998 to 2004, the price of gasoline fluctuated between $1 and $2 USD per U.S.
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".
The price of gas varies during the summer and winter months.Źródło: https://en.wikipedia.org/wiki/Gasoline
Gasoline also known as petrol 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.Źródło: https://en.wikipedia.org/wiki/Gasoline