Ford Fokus>> System of greasing of the engine>> Engine oil
Oil prevents a dry friction and deterioration of pistons, cylinders, and also all bearings of a cranked shaft and клапанного the mechanism. Besides, engine oil in addition condenses a backlash between the piston and cylinder walls. Oil also incurs cooler function, taking away heat from internal walls and engine details. Besides, it protects from corrosion, keeps working off particles in a suspension and connects a part of chemical products of combustion.
Modern engine oils are the lubricant received from refined oil. Manufacturers of oils add to them special additives which make to 20 % from engine oil. Additives, in particular, protect oil from process of oxidation and prevent its foaming on high turns. One of vjazkostno-temperature characteristics is the index of viscosity VI is an empirical, dimensionless indicator for an estimation of dependence of viscosity of oil from temperature. The above numerical value of an index of viscosity, the is less viscosity of oil depends on temperature. Oil with a high index of viscosity has the best fluidity at low temperatures and higher viscosity at working temperature of the engine. Engine oil service life is influenced by such factors, as water presence, quality of fuel and burning products. Therefore regular change of oil is obligatory.
Synthetic engine oil is in most cases more expensive than the mineral. The initial high price is compensated by decrease in the expense of oil and fuel and interval increase between oil replacement.