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Synthetic vs. conventional oil

Synthetic vs. conventional oil

The importance of engine oil

Your engine is a complex machine with hundreds of moving parts that operate under a wide range of temperatures and stressors. The oil you select needs to be equally capable of coping with these operating conditions to protect your engine against wear, corrosion, and the build-up of dirt and deposits.

What’s the difference between conventional and synthetic oil?

Conventional oil begins in the ground. It’s simply refined crude oil. But synthetic motor oil (whether full synthetic oil or a synthetic blend oil) is born in the lab.

Synthetic oil is not only refined but also distilled, purified and broken down into its basic molecules. It is then rebuilt and enhanced with additives so that it can better protect against engine wear, extreme temperatures and sludge build up. This process not only removes more impurities from the crude oil but also enables individual molecules in the oil to be tailored to the demands of modern engines. These customized molecules provide higher levels of protection and performance and can keep your engine running better for longer.

What are the benefits of synthetic oil?

Helps to keep your engine cleaner


As oil circulates through your engine it can pick up deposits. Over time, conventional oils can sometimes form sludge, which can reduce your engine’s efficiency and, ultimately, reduce the life of your engine. Synthetic motor oils contain fewer impurities compared to conventional motor oils and can better resist the formation of sludge, thereby preventing deposits from forming in your engine.

Offers greater engine wear protection

Engine parts are in constant contact with each other. They’re also moving at high speeds. In the extreme environment of your engine, components can wear and break down. Your motor oil is the protective barrier between these components. As conventional oils break down, their ability to prevent engine wear diminishes. Synthetic oils, on the other hand, retain their wear protection properties for a much longer time, increasing engine life.

Flows better in low temperatures

When your car sits for a while (let’s say overnight) the oil settles when you fire up the ignition, it begins flowing through critical engine parts to protect against friction. With conventional oils, it takes more time until they are able to flow smoothly through the engine.

During the cold winter months, or if you live in an extremely cold environment, this flow process takes even longer. Synthetic low viscosity oils, however, are engineered to flow quickly even at low temperatures, and they start protecting your engine right after you start your car.

Protects better at high temperatures

When running, engines are hot. Really, really hot. Over time, the high temperatures in your engine can cause conventional motor oils to break down or evaporate exposing your engine to wear. Synthetic motor oils are engineered to resist these high temperatures, which is especially important if you’re driving in hot climates.

Protects critical turbocharger parts

To meet consumer demand, automakers are building cars with smaller engines (for greater fuel efficiency) but adding turbochargers (to boost power). We already mentioned how engines run at high temperatures, which can break down conventional oils faster, but today’s turbocharged engines are even more aggressive. The shaft inside a turbocharger can spin upwards of 200,000 revolutions per minute, so it’s critical that your motor oil can get to that shaft and lubricate it properly very quickly.

Conventional oils can break down faster under these conditions and leave deposits on turbocharger components, which can lead to failure. Synthetic oils can protect these components much better than conventional oils, keeping them operating at peak performance and boosting your engine’s power. Find out more on how our engineers develop new products and continually refine the entire range of ExxonMobil products. 

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