Engine Oil

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Engine oil lubricates moving metal parts of an internal combustion engine and averts overheating and excessive wear and tear. The microscopic particles resulting from the friction of the moving metal parts are held in suspension by the engine oil. Engine oil saturated with metallic particles turns a darker shade and is unable to deliver optimum performance. Engine oil contaminated with metallic particles will cause excessive wear and tear and therefore must be replaced at manufacturer recommended intervals.

During service, the contaminated engine oil is completely drained out and is replaced by fresh oil. 

The different types of engine oil are mineral, semi-synthetic and synthetic. 

Service intervals are determined by the type of engine oil used. Mineral engine oils should be replaced at 5,000km intervals, while synthetic engine oils have an interval of 10,000km.

Engine oil containers have a combination of numbers and a letter. For example, in 10W30. 10 is the viscosity of the oil in cold temperatures while the number after W tells you the viscosity of the oil when the engine is operating under normal temperature. 

Reputed brands of mineral engine oil cost Rs 370 for three litres, while synthetic engine oil costs Rs 2,700 for three litres. Castrol, Petronas, Shell and Mobil1 are reputed brands of engine oil.