Oil UK

Almost all lubricating oils used today, with the exception of some quenching oils and some low quality hydraulic oils, contain additives.

The additives are made in special additive processing plants, not in refineries. They are not naturally occurring substances.

Additives are added to to the lubricating base stock in the blending kettle. The oil is normally heated to around 50 to 60 0C, before addition of the additives. Then the mixture is thoroughly churned and mixed for about 2-3 hours. This makes sure that the additives have dispersed fully in the base oil. The additive can be either pumped into the kettle or, for smaller quantities, manually added to the kettle.

Synthetic oils are man made lubricants which were originally created for jet aircraft engines. They have a wide range of performance and can protect the engine at very high oil temperature conditions. In other words , they have exceptional thermal stability. Where conventional oils would turn to jelly at very low temperatures and could break down at very high temperature , synthetic lubricants manage to remain fluid at these temperatures and give adequate lubrication where it is needed most.

The single most important thing you can do to get long life from your engine is to change your engine oil and oil filter as often as recommended by your car manual. Motor oil that properly lubricates the engine system during the initial part of life can become thick towards the later stages of its sump life. It then cannot flow as required and also blocks the oil filter. This may cause engine damage and seizure in extreme cases.

API stands for American Petroleum Institute a body which specifies the standards that high Quality oils must meet. In most typical passenger car motor oils , the letters API are followed by a set of two letters such as SJ , SH etc. These standard levels have evolved through the years in response to the changing passenger car engine technology which imposes certain conditions on the quality that most run in it . The highest API for PCMO's today is API-SN.

Diesel Engine Oils have an API standard with the letter 'C' such as CF , CG etc. The current highest DEO standard is CI meant for use in high speed modern four stroke engines. However DEO's are popularly classified under the MIL (US military)standards. Popular specification are MIL-B, MIL-C

SAE stands for the Society of Automotive Engineers. The SAE grade specifies the most important parameter for engine oil mainly its viscosity. In other words it tells you the "thickness" of the oil. The lower the number , the "thinner " the oil

'W' signifies the winter rating of the oil, showing that it will perform well in cold weather. The lower the number prefixing the 'W' , the cooler is the temperature oil can withstand.

Multigrade oil carries 2 ratings - a winter and a summer rating. A greater difference between these figures indicates a broader range of operating temperatures. Multi-viscosity grades or multigrades as they are popularly known are oils which are suitable for use over a wide temperature range.

What other kinds of base oils are available in the world?

The right SAE rating for oil is shown in your car manual. The most widely used grade in the UK currently is 10W40, but be sure to use the viscosity grade recommended for your car.

Synthetic oils may sometimes give a longer drain period than conventional motor oils, but this depends more on the engine technology, so do follow the manufacturer's recommendation, rather than the drain period

The main disadvantage of synthetic lubricants is that they are inherently more expensive than mineral oils, and are limited in supply. This limits their use to speciality oils and greases that command premium prices. Esters suffer further disadvantage of greater seal-swelling tendencies than hydrocarbons: so, caution has to be exercised in using them in applications where they many contact elastomers designed for use with mineral oils.

The main disadvantage of synthetic lubricants is that they are inherently more expensive than mineral oils, and are limited in supply. This limits their use to speciality oils and greases that command premium prices. Esters suffer further disadvantage of greater seal-swelling tendencies than hydrocarbons: so, caution has to be exercised in using them in applications where they many contact elastomers designed for use with mineral oils.

ADDITIVE	WHAT IT DOES	HOW IT WORKS
Oxidation Inhibitor	Prevents varnish and sludge formation on bearings or in circulating systems. Retards aging of the oil. Lengthens service and storage life of oil. Protects oil itself directly (indirect protects metal parts - varnish and acids)	Reacts more readily with oxygen (from air) than does the oil itself, thereby retarding oxidation of the oil.
Rust Inhibitor	Prevents rusting of ferrous (iron or steel) machine parts	Forms a film on ferrous metallic parts thus protecting them from attack by water or other destructive material.
Corrosion Inhibitor	Prevents corrosive attack on non-ferrous metallic surfaces	Forms a film on non-ferrous metallic parts thus protecting these parts from attack by contaminants in the oil.
Detergent	Prevents oxidation products (sludge) which have formed in oil from sticking to metal components. May also remove deposits already formed on metallic components. Usually combined with dispersant additive	By chemical reaction, oxidation products (sludge) remain soluble in the oil and do not stick to the metal surfaces.
Dispersant	Keeps oxidation products separated and suspended in the oil. Retards formation of sludge	By chemical reaction, oxidation product particles are kept small enough to allow them to float in the oil.
Foam Inhibitor	Causes foam to dissipate more rapidly	Protects combination of small bubbles into large bubbles which in turn burst more easily.
Viscosity Index (V.I.) Improver	Reduces rate of change of viscosity with temperature	Additive thickens with increasing temperature thereby preventing oil from thinning out too rapidly
Pour Depressant	Lowers the Pour Point	Keeps small wax crystals apart thus preventing the formation of large crystals which would stop the flow of oil.
Antiwear agent	Minimizes wear caused by metal-to-metal contact during conditions of mild boundary lubrication e.g. starts and stops	Additive reacts chemically and forms a film on metal surfaces under normal operating conditions
Extreme Pressure (E.P.) Agent	Prevents welding and subsequent wear or seizure of contacting metal parts under extreme or shock load conditions.	When metal-to-metal contact occurs (as under extreme or shock load conditions), the heat generated at the point of contact causes the additive to react chemically with the metal. The new compound formed between the metal surfaces reduces friction and prevents welding or seizure.
Tackiness Agent	Increases the adhesive properties of a lubricant - improves retention and prevents dripping and spattering	High molecular weight compounds are added to the oil thereby increasing its viscosity and improving its adhesive properties.
Emulsifier	Promotes rapid mixing of water and oil resulting in the formation of a stable emulsion (e.g. water-soluble cutting oils)	Reduces interfacial tension and permits intimate mixing of oil and water.
Fillers for Greases Molybdenum disulphide (Moly-Sulfide) Zinc Oxide	Imparts load-carrying and anti-wear characteristics to a grease. Imparts some load-carrying characteristics. Gives a white color to the grease	Unique laminar structure sticks to metal parts Fine white powder mixes readily with grease