What Are Fully Synthetic, Semi-Synthetic And Mineral Engine Oil?

What's the difference between a mineral, semi and fully synthetic engine oil? Which one is right for you?

If you want to talk about getting the most out of your ownership experience with a car, one of the best ways to improve longevity is to pick a good engine oil. Oil happens to be the lifeblood of the engine as it lubricates engine components and reduces friction. 

The one you select can greatly impact how quickly (or slowly) an engine wears out. Engine wear is an unavoidable fact of life, and all we can really do is slow it down or mitigate it.

If you don't know much about engine oils and wonder what you should be using on your car, you've come to the right place, as this article will discuss the different types of engine oil and their pros and cons.

There are technically two types of engine oils in the market, namely mineral and synthetic. But in 1966, legendary engine oil manufacturer Motul introduced a more affordable version of fully-synthetic oil, called semi-synthetic.

So which one should you choose? Let's discuss it down below.

Mineral Oil

Mineral oils are directly derived from refined crude petroleum oil. They are the cheapest because there's not much engineering going into them. The only refinement process that goes through it is the removal of natural contaminants and unwanted hydrocarbons. 

For running-in freshly built engines, a good mineral oil is important as it allows the various components to bed in properly. But because they do not have additives, their molecular structures break down fast, so you need to change them frequently.

Fully Synthetic

Fully Synthetic oils are chemically modified oils with additives and have fewer impurities. The additives are added to suit what an engine needs such as good flow at low temperatures and stable viscosity at high temperatures.   

There's no debate that fully synthetic oil is the best kind of oil to put in your engine, regardless of age or design. It usually has the most additives and is the most resistant to temperature and abuse, so it would be our oil grade of choice whether dealing with a 30-year-old classic car, or a brand new Honda HR-V.

Semi-synthetic

Semi-synthetic oil is more expensive than mineral oil but cheaper than fully synthetic. The simple reason for this is that they are a mix of the two.

Although they can provide the same protection features as fully synthetic oils, they are less potent than fully synthetic oils. As a result, they are often used as an economical alternative to fully synthetic oils for people that do not need a maximum amount of performance and engine protection. They are commonly used in high-mileage engines, as the engine deterioration has already taken its course in high-mileage cars.

Buyer Beware

Picture credit: Kosmo

What has been increasingly common lately are fake oils entering the market – especially on online platforms. These oils are being sold for surprisingly low prices and can in fact damage your engine if you’re not careful. Always make sure that you’re getting your oil from a reputable source as you will have no idea what the actual oil content is in a fake product.

The same can go with oil filters, which we recommend changing with every oil change as well. Filters have a big impact on keeping your oil clean, and between a fake and an original filter, there is a huge difference in actual filtering ability. Some aftermarket filters boast longer service intervals but we recommend against them as there is no guarantee that they are 100% effective.