What to do when your car is broken?

Dodane: 14-08-2016 03:46
What to do when your car is broken? oil for Hummer

Checking the Brake

The car, which go in the winter requires special care and protection. Driving over short distances, even during the hard frost is not a problem, but the car must be carefully prepared, if we want to go before the winter holidays. Then we should buy a proper engine oil, which is resistant to low temperatures, and also check the performance of our tires. Some people, although they can drive with winter tires all year round, but in the case of departure for further route is better to replace tires on decent winter tires. We should also bear in mind that driving in winter requires an efficient automobile brakes because the car much more likely to be exposed to the need for hard braking.


Check your car before you set off on a long journey

Summer is the time when we will be happy to travel. Many people choose when car - you can get quite big luggage, stop for a rest at any place, and on the way to visit all the interesting places that only see. However, this trip was a real pleasure, it is necessary to ensure the efficiency of the car. A thorough review before the trip is an excellent opportunity to catch any defects or prevent serious damage mechanisms and systems. So if you are planning a family vacation, remember about the car. In the end, the most important is the safety of our loved ones, and the only efficient car can provide it during the long route.


Properties

Most motor oils are made from a heavier, thicker petroleum hydrocarbon base stock derived from crude oil, with additives to improve certain properties. The bulk of a typical motor oil consists of hydrocarbons with between 18 and 34 carbon atoms per molecule.7 One of the most important properties of motor oil in maintaining a lubricating film between moving parts is its viscosity. The viscosity of a liquid can be thought of as its "thickness" or a measure of its resistance to flow. The viscosity must be high enough to maintain a lubricating film, but low enough that the oil can flow around the engine parts under all conditions. The viscosity index is a measure of how much the oil's viscosity changes as temperature changes. A higher viscosity index indicates the viscosity changes less with temperature than a lower viscosity index.

Motor oil must be able to flow adequately at the lowest temperature it is expected to experience in order to minimize metal to metal contact between moving parts upon starting up the engine. The pour point defined first this property of motor oil, as defined by ASTM D97 as "... an index of the lowest temperature of its utility ..." for a given application,8 but the "cold cranking simulator" (CCS, see ASTM D5293-08) and "Mini-Rotary Viscometer" (MRV, see ASTM D3829-02(2007), ASTM D4684-08) are today the properties required in motor oil specs and define the SAE classifications.

Oil is largely composed of hydrocarbons which can burn if ignited. Still another important property of motor oil is its flash point, the lowest temperature at which the oil gives off vapors which can ignite. It is dangerous for the oil in a motor to ignite and burn, so a high flash point is desirable. At a petroleum refinery, fractional distillation separates a motor oil fraction from other crude oil fractions, removing the more volatile components, and therefore increasing the oil's flash point (reducing its tendency to burn).

Another manipulated property of motor oil is its Total base number (TBN), which is a measurement of the reserve alkalinity of an oil, meaning its ability to neutralize acids. The resulting quantity is determined as mg KOH/ (gram of lubricant). Analogously, Total acid number (TAN) is the measure of a lubricant's acidity. Other tests include zinc, phosphorus, or sulfur content, and testing for excessive foaming.

The NOACK volatility (ASTM D-5800) Test determines the physical evaporation loss of lubricants in high temperature service. A maximum of 14% evaporation loss is allowable to meet API SL and ILSAC GF-3 specifications. Some automotive OEM oil specifications require lower than 10%.

Źródło: https://en.wikipedia.org/wiki/Motor_oil