FORD SCORPIO

1985-1994 of release

Repair and car operation

2.24. Recommendations about engine oils

THE GENERAL DATA

Viscosity of oil

Viscosity characterises fluidity of oil. Depending on temperature oil tends to fluidity reduction. In process of increase in temperature oil becomes more fluid. It worsens ability of oil to сцепляемости and stability to maintain high contact pressure. At cooling oil gets denser, fluidity decreases and the internal friction increases. Because of this property it is necessary to apply engine oil with such viscosity which varies at change of temperature in probably smaller limits.

Fluidity of oil is equivalent to its internal friction and is designated by units SAE (Society of Automotive Engineers – Association of Automobile Engineers), for example SAE 30, SAE 10. High indicator SAE means that oil dense, low – characterises liquid oil. Nevertheless, viscosity of oil completely does not characterise lubricant properties of oil.

ALL-WEATHER OILS

In engines of cars it is preferable to use all-weather oils. They are made on the basis of liquid one-seasonal oil (type 10W). In нагретом a condition this oil is stabilised by a so-called thickener that provides corresponding lubricant qualities of oil at all temperatures. At use of all-weather oil, it is necessary to apply grades with a wide temperature range of viscosity, for example 10W-40, 15W-50.

Letter W (winter – winter) in designation SAE characterises suitability of use of oil during the winter period.

OIL WITH THE RAISED LUBRICANT PROPERTIES

Oils with the raised lubricant properties represent all-weather oils in which, besides other additives, there are the substances reducing factor of a friction that provides reduction of the expense of fuel by 2 %. By their manufacture special initial components (synthetic oils) are used. At purchase of such oil it is necessary to pay attention to that this oil was authorised to application by firm Ford.

ENGINE OILS

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The prevention

Additional additives to oil, irrespective of their kind and appointment, should not be added in oil.

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For modern engines it is necessary to use only oils HD. Oils HD are oils with the raised lubricant properties improved at the expense of various additives. These additives provide the best anticorrosive protection, more favorable conditions against the oxidation phenomenon, the least propensity to formation of slags, the best change of the viscosity, clearing and dissolving properties. Clearing and dissolving additives not only reduce formation of the rests in the engine, but also ability these rests and all other pollution in engine oil simultaneously possess to dissolve and hold in a suspension so that at oil replacement these pollution leave together with merged oil.

Quality of oils HD is defined on system API (American Petroleum Institut). The European manufacturers also adhere to this system.

The designation of a grade of oil is made by two letters. The first letter characterises a scope: S – Servise, are intended for carburettor engines; With – Commercial, are intended for diesel engines. The second letter defines an oil grade in alphabetic order.

Premium oils on classification API are SG for carburettor engines and CD for diesel engines.