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Synthetic oil vs. conventional oil

Top 5 synthetic motor oil FAQs

Is synthetic oil better than conventional oil? Should I consider changing from conventional oil to synthetic oil? What’s the real difference between full synthetic, synthetic blend and conventional oil? Find the answers to the most frequently asked questions here.

5. Is synthetic oil better for my engine than conventional oil?

Yes, synthetic oil is better for your engine than conventional oil. Although conventional oil (i.e., mineral oil) can provide adequate lubrication performance, it can’t compete with the overall engine performance and protection provided by synthetics.

Synthetics use higher quality base oils as compared to the less-refined base oils used in conventional oils which makes conventional oils:

  • Less chemically stable
  • Oxidize and acidify more easily
  • Quicker to break down and lose protective qualities

Overall, full synthetic oils provide better engine performance and protection than conventional and synthetic blend motor oils. Mobil 1™ advanced full synthetic motor oils are specially formulated with a tailored additive system that provides additional performance benefits above and beyond those found with conventional and synthetic blend oils by:

  • Combating sludge and deposit buildup
  • Reducing wear
  • Protecting against high temperatures
  • Controlling oil breakdown

So all of the chemistry that starts in a lab really makes a big difference on the road.

4. What are the advantages of synthetic oil over conventional oil?

Synthetic oils are created through complex processes, including being chemically developed from petrochemicals, to have the exact molecular qualities needed for a specific application.

These processes remove impurities from the crude oil and enable individual molecules to be tailored to the demands of modern engines. These customized molecules in synthetic oils provide higher levels of performance and protection than conventional oils.

So how do synthetic oils outperform conventional oils?

  • Synthetic motor oil for engine wear protection

    By offering greater engine wear protection

    Engine parts are in constant contact with each other and moving at high speeds. In the extreme environment of your engine, components can wear and break down. Your motor oil is the only protective barrier between these components.

    As conventional and synthetic blend oils break down, typically, their ability to prevent engine wear diminishes. But Mobil 1 full synthetic oils retain their wear protection properties for a much longer time, helping to increase engine life by keeping important engine parts in excellent condition for 250,000 miles.*

    *Total engine miles. Tested in vehicles primarily in city and highway driving conditions with respective product recommended oil change intervals.

  • Engine shown in vehicle

    By keeping your engine cleaner

    As oil circulates through your engine, it can pick up deposits. Over time, conventional oils can form sludge, which can reduce your engine's efficiency and, ultimately, reduce the life of your engine. Mobil 1 full synthetic oils contain fewer impurities compared to conventional and synthetic blend oils and can better resist the formation of sludge and deposits in your engine. If your engine already has sludge, Mobil 1 motor oils clean up virtually all engine sludge in just one oil change.

  • Mobil 1™ oil in car driving in cold weather with snow on ground and trees

    By flowing better in low temperatures

    When your vehicle is not being driven, the oil settles. But when you fire up the ignition, it begins flowing through critical engine parts to protect against friction. Conventional and synthetic blend oils take more time until they are able to flow smoothly through the engine. During cold winter months, or if you live in an extremely cold environment, this flow process takes even longer. Mobil 1 full synthetic oils are engineered to flow quickly even at low temperatures, and they start protecting your engine right after you start your vehicle.

  • Synthetic oil in car protects in desert high temperatures

    By protecting better at high temperatures

    When running, engines are hot. Over time, the high temperatures in your engine can cause conventional and synthetic blend oils to break down or evaporate, exposing your engine to wear. Mobil 1 full synthetic oils are engineered to resist these high temperatures, which is especially important if you’re driving in hot climates or requiring your engine to work harder such as while towing or hauling.

  • Synthetic oil protects turbocharger engine parts

    By protecting critical turbocharger parts

    Automakers are building cars with smaller engines (for greater fuel efficiency) and turbochargers (to boost power). Turbocharged engines run even hotter than non-turbo engines. Oil in a turbocharger can exceed 400° Fahrenheit and the shaft inside a turbocharger can spin upwards of 200,000 revolutions per minute, so it’s important that motor oil flows quickly to these critical parts for proper lubrication.

    Conventional and synthetic blend oils can break down faster under extreme turbo conditions and leave deposits on turbocharger components, which can lead to failure. Mobil 1 full synthetic oils can protect these components much better than conventional oils, keeping them operating at peak performance and boosting engine power. conventional oils, keeping them operating at peak performance and boosting your engine’s power.

3. Does synthetic oil have longer oil change intervals than conventional oil?

Yes, generally, synthetic oil can provide longer oil change intervals than conventional oil. But this is often dependent upon the brand of motor oil and several other factors, such as driving style and driving conditions. Please follow the recommendations in your owner's manual while your vehicle is under warranty.

Some synthetic motor oil brands still recommend oil changes every 3,000 or 5,000 miles. The Mobil 1 lineup includes full synthetic motor oils that support oil change intervals ranging from 7,500 miles, to 20,000 miles or one full year .†

†Whichever comes first.

2. What is the difference between a full synthetic oil and a synthetic blend?

While there are no firm industry definitions, full synthetic motor oils typically use the highest quality base oil combination as a starting point. Synthetic blend motor oils will typically be either a blend of high-quality and lower-quality conventional base oils or all high-quality (higher than conventional) base oils. But the synthetic base oil is only half the story. The correct blend of additives must go into the mix to create the oil.

The tailored additive system in Mobil 1 full synthetic oils gives the additional performance benefits above and beyond those found with synthetic blend oils. And while full synthetics as a motor oil category provide better protection than conventional and synthetic blend oils, not all synthetics are created equal.

1. My car doesn’t require synthetic motor oil. Can I change from conventional motor oil to full synthetic motor oil?

Switching from conventional motor oil to full synthetic motor oil is perfectly acceptable. Mobil 1 full synthetic motor oils are compatible with conventional oils, oils for high mileage vehicles, synthetic blends and other full synthetic oils. Engine flushing is not required.

For high mileage engines

However, if your vehicle has a high mileage engine (e.g., engine with more than 75,000 miles) that has never used synthetic motor oil, or one that has been poorly maintained with infrequent oil changes, we recommend easing into extended oil change intervals to allow Mobil 1 oil to clean up the engine. In these cases you should still follow the same basic oil change procedures (drain the old oil, remove the old oil filter, put in new Mobil 1 oil and put on a new oil filter).

Follow your OEM’s recommended maintenance practices regarding oil changes, but you should follow more frequent (one or two non-extended drain) oil changes when first switching to synthetic oil. The reasoning behind these shortened oil change intervals is that a high mileage engine, or one that has had a lack of maintenance (including infrequent oil changes), will likely have a considerable buildup of sludge and deposits.

Mobil 1 oil will help clean the engine as you drive, but it will have to work much harder in a very “dirty” engine and so it is best to change the oil more frequently for those first several thousand miles. After that, you can rest assured that Mobil 1 oil is continuing to keep your engine running clean and well lubricated for mile after mile.

A quick word from eHow’s Auto Center

Synthetic? Conventional? Hear automotive expert Chris Duke share his knowledge on the topic.