For a car maniacs - about oils and car service

at are to serve as vehicles for collective are fully operational and ensure the safety of passengers. Servicing buses should take place after the establishment of any problems with the vehicle, which can occur while driving or be

For a car maniacs - about oils and car service Audi smoking exhaust


Replacing the engine oil busses

Allowing buses to carry passengers takes place after checking their technical condition. Inspection of road traffic requires that all vehicles that are to serve as vehicles for collective are fully operational and ensure the safety of passengers. Servicing buses should take place after the establishment of any problems with the vehicle, which can occur while driving or be determined at a standstill. Due to the fact that in Poland passenger transport by buses organized frequently by private carriers, who must themselves cover the costs of buying new vehicles, they try to take care of their vehicles so that they can ride as long as possible. One way to prolong the life of vehicles is a frequent replacement of engine oil.


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


car under control

Minor repairs of the car does not usually require a lot of time or money. Often, however, we ignore this type of failure - after all, they are not dangerous, and nowadays many people find it difficult to find even a brief moment to drive the mechanics and to verify the minor faults. Of course, this is a mistake. Few serious problem, which will be mishandled, could adversely affect other mechanisms and systems of the car. So if the failure is not remedied, it is likely to contribute to a much larger damages, and hence - the cost of repairs will increase significantly. Often in such a situation replacement parts are required, which of course affects the final price of the service mechanic. Not so it is worth delaying the service of the car, even if the problem with him seems to be harmless.