Contents: Engine oil contamination ↳ Dilution of motor oil in gasoline… ↳ Viscosity of motor oil ↳ All-season oil ↳ Low friction oil ↳
Engine oil contamination
Depending on the operating conditions, completely different requirements are imposed on motor oils. Therefore, it is very difficult to prescribe the right lubricant for operation under different operating conditions. In engines that operate for a long time at high crankshaft speed or at full load, the motor oil heats up to a high temperature. Under the influence of high temperature and atmospheric oxygen, the oil begins to oxidize. Oxidation products increase the viscosity of the oil and can be deposited in the form of a varnish film on the upper part of the pistons, in the ring grooves and on the valve stems. This can lead to coking of the valve heads.
Dilution of motor oil in gasoline engines
If the fuel-air mixture supplied to the cylinders is too rich, if the engine rarely operates at full load or is not warmed up enough (driving in urban conditions), the fuel does not burn completely. Soot, oil carbon and other products, unburned fuel and moisture condensate cause the formation of sludge, acids and asphalt. Unburned fuel settles on the cold cylinder walls and, flowing into the crankcase, washes away the oil film from the working surfaces of the cylinders and pistons. As a result, the lubrication of the working surfaces deteriorates and the engine oil dilutes, due to which, depending on the fuel content in the oil, the lubricating properties of the oil deteriorate. If the oil is very diluted, it must be changed earlier. Since gasoline particles evaporate from the oil during intense driving (with a hot engine), it is necessary to check the engine oil level more often, especially in winter (many cold starts - high gasoline content in the oil).
Viscosity of motor oil
Viscosity is the fluidity of oil. Under the influence of temperature, each oil tends to change its fluidity. As the temperature increases, the oil becomes very fluid. This has a negative effect on the adhesive and load-bearing capacity of the oil film. In the cold, the oil becomes thick, its viscosity increases, and the internal friction in the lubricant layer increases.
When the engine is cold, the oil should still be fluid enough not to make the starter too difficult to operate and to reach all lubrication points as quickly as possible when the engine starts running. All this requires the use of motor oils whose viscosity changes as little as possible with temperature changes.
Flowability or viscosity is comparable to the internal friction of the oil and is classified according to the SAE (Society of Automotive Engineers) system, such as SAE 30, SAE 10, etc. Large numbers refer to thick oils, and small numbers to thin oils. However, the viscosity of the oil does not allow any conclusion to be made about its lubricating properties.
All-season oil
All-season oils must be used for FORD SCORPIO engines. This has the advantage that the oils do not have to be changed with the onset of a new season (summer/winter). All-season oils are produced on the basis of low-viscosity seasonal oil (e.g. 15 W). Thanks to the so-called thickener, the oil is stabilized in a hot state, so that the required lubricating capacity is achieved in each operating mode.
The W symbol in the SAE classification indicates winter oil.
Low friction oil
Low friction (energy-saving) oils are all-season oils that, among other additives, have friction modifier additives, due to which fuel economy increases by 2%. Low friction oils have low viscosity (for example, 10W30). The base oil for low friction oils is synthetic oil. When buying low friction oil, you should make sure that it is approved for use by FORD for SCORPIO car engines.