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Understanding the label – What’s in an oil?

As the invisible partner enabling us on life’s journeys, do we truly understand what the differences in the various oils are, what the labels on our oil cans mean, and what exactly they do for our engines?

Oil is undoubtedly the lifeblood of your car. If the wrong oil is used, the engine is at risk of increased wear and corrosion. Formation of blockages can also lead to engine seizure. However, by making use of Shell Helix oil in the engine, you can carry on motoring with confidence and experience the feeling that your car has just been serviced – all for less than the cost of a tank of fuel.

By cleaning the engine, oils are designed to clear away dirt, debris and deposits from engine components and to prevent blockages in important oil ways. The oil helps to lock up the dirt and render it harmless until it is removed at the next oil change.

“By reducing friction and minimising wear, premium lubricants such as Shell Helix oils form a protective film over your engine components and have special additives that act between the moving surfaces to prevent contact and reduce drag,” explains Anton Niemann, General Manager Lubricants at Shell Downstream South Africa. “This helps your engine to operate as quietly and effectively as the designers intended.”

Conventional mineral vs synthetic

Innovation and research has evolved to include synthetic and fully-synthetic lubricants to the oil shelf that once only stocked conventional mineral type oils.

Many would have heard the terms synthetic oil or conventional mineral oil, but do we understand the differences? While most new vehicles would require synthetic oils, older models would be able to make use of the conventional mineral and somewhat regular lubricant.

In a synthetic form, the engine lubricant consists of a base oil, powder additives, and a carrier oil that enables the even distribution of the additives. And while both synthetic and conventional mineral oils are derived from highly refined crude oil, the differences lie in their level of refinement.

The refinement process allows for the scientists who create the oil the complete control over the lubricant’s molecular size as well as its purity. These factors are crucial in ensuring that they create a chemical which lowers friction, reduces engine sludge, and increases overall engine performance.

Mineral motor oil is the fraction of naturally occurring crude oil with the right properties for lubricating engines. Synthetic oil is generally considered the premium blend oil. It is designed for performance. However, that same manufacturing process makes it more expensive.

“Shell Helix semi-synthetic or ‘synthetic technology’ oils make use of both synthetic and mineral base stocks to achieve higher performance levels than can be formulated from mineral oils alone,” adds Niemann. “Our revolutionary fully-synthetic motor oil is made from natural gas, not crude like other synthetics and designed to give you the ultimate performance.”

“The technological advantages associated with synthetic lubricants are numerous. These include aspects such as the uniform molecular size of the lubricant means less friction; improved fuel consumption; greater function in cold and extreme weather conditions; and the additives boost overall protection as well as cleaning engine internals.”

There is however a lot of confusion from the majority of the public as to which oil is the correct one for their vehicles and applications, and with a lot of numbers appearing on the bottle, do we really know the meaning behind these?

What do the numbers mean?

While vehicle manufacturers will indicate the specific engine oil required for the correct operation of your vehicle, at times, the DIY mechanic may not be all too aware which lubricant to choose.

It is essential to consider an engine oil that is endorsed by the American Petroleum Institute (API), and given a rating which would meet the OEM quality standards. This said, the crucial factor to be aware of is the viscosity rating of the oil. The viscosity of a motor oil is determined by how thick it is. The oil must be thick enough to adhere to the components as it passes by to provide adequate lubrication; however at the same time, it must be thin enough to flow through the system.

“An engine lubricant is given a viscosity grade based on how it operates upon a variety temperatures,” comments Niemann. “It is imperative that it operate as intended in both heat and cold environment. It is for this reason, amongst others, that many modern oils have viscosity index improver additives included to ensure that it maintains the correct thickness for hot and cold temperature.”

Apparent on the majority of credible multi-grade engine oils, two sets of numbers are usually present. The first number is typically a 0, 5, 15, 20, or 25; followed by a W representing winter; while second number is for the viscosity in hot summer conditions and temperatures, and it may be represented by the numbers 20, 30, 40, 50 or 60.

“For example, a common lubricant grade may be considered as a 5W-30, with the 5W showing a viscosity rating of 5 when the engine internals are cold,” he says. “This rating is considered rather thin when compared to others, and will begin to flow even before the engine has warmed up. The second number, in this case 30, is the viscosity rating once the engine is warm, with the 30 rating proving not too thin to provide adequate lubrication for the internal components of the engine.”

It is imperative to make use of the correct engine lubricant in order to avoid internal damage and to ensure that the internals of an engine ore lubricated and in correct operating order. The resultant factor is making use of the incorrect oil with an incorrect viscosity will shorted the life or an engine due to an increase of metal-to-metal friction. This in turn will result in serious damage to engine components, which will most definitely require costly repairs.

“It is for this very reason that Shell has launched the Shell LubeMatch tool on its website which allows consumers the ability to research exactly which engine oil is the correct lubricant for their specific vehicle,” concludes Niemann.