Wikipedia about oil
An oil is any neutral, nonpolar chemical substance that is a viscous liquid at ambient temperatures and is both hydrophobic (immiscible with water, literally "water fearing") and lipophilic (miscible with other oils, literally "fat loving"). Oils have a high carbon and hydrogen content and are usually flammable and slippery.
The general definition of oil includes classes of chemical compounds that may be otherwise unrelated in structure, properties, and uses. Oils may be animal, vegetable, or petrochemical in origin, and may be volatile or non-volatile. They are used for food, fuel, lubrication, and the manufacture of paints, plastics, and other materials. Specially prepared oils are used in some religious ceremonies as purifying agents.
Gasoline in the USA
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.
Replacement of fluids in the car
Every driver must remember that it is obliged to, to review the technical condition of the car owned by them every twelve months. On this basis, the car will be allowed to move, and employee service centers will be able to sign the book of the motor vehicle. During the visit, the service car will be made the necessary car repair in greater or lesser extent. Sometimes you may find that the cause of engine problems is the old fluid motor, which has ceased to perform its function. Similarly, for example, brake fluid, and therefore service personnel make the exchange of fluid in the car his client.