Oil is the lifeblood of internal combustion cars' engines, and it needs to be maintained and carefully considered to get the best mileage, efficiency, and longevity out of your engine. With this in mind, what is the best oil for your car? This isn't exhaustive, as oil can be a deep topic to nerd out over. This will just be surface-level to give you an idea of what's good for you.
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What's currently there?
Engine oil has had some major advancements in recent years. The prime purpose is lubricating various internal engine components for less friction and, therefore, less wear and tear. Motor oil creates a separating film that minimises direct contact with moving components. However, the execution of such has improved drastically. It's worth noting SAE is an acronym for the Society of Automotive Engineers that sets the standard for how oils are graded and tested. SAE is an acronym you'll typically see, so don't let that confuse you. Viscosity, temperature range and oil type are the things you'll typically look at when choosing oil. Additives have come into the fray, but in our view, they're more nice to haves than necessities.
Viscosity?
Viscosity refers to the thickness of the oil. Scientifically, it measures a fluid's resistance to flow and can change depending on the temperature. When you pull into a petrol station, the attendant will often ask if you need oil and what particular weight you need. The SAE established a system for grading oils named the SAE J300, a standard used globally. SAE J300 looks at monograde and multi-grade oils. Monograde oils are typically coded as SAE 30, dictating the oil's thickness when the engine is at operating temperature. Whereas multigrades are typically coded as SAE 15w30, for instance, because multigrade oil consists of a winter grade that specifies the oil's thickness at cold temperatures and when the vehicle is at operating temperature. The 'w' refers to winter, meaning in our example above, the '15' indicates the oil's flow rate when cold. Then, the number after that is the flow rate when hot. The changing seasons affect this; the colder it is, the thicker the oil will become, making it flow slower through your engine. Viscosity is important as engines are designed around a particular viscosity for several reasons, like maintenance, efficiency, power and how much wear can be reduced.
Synthetic oils or Mineral oils?
There's no one true best oil, but Synthetic oils have been a popular choice recently.
Synthetic Oils came about due to insufficient quantities of crude oil needed by German scientists in the late 1930s. They were a means to substitute mineral oils, but they are superior in function compared to mineral oils. Synthetic oils showed that they managed harsh conditions and tended to perform longer. This is evidenced by longer oil change intervals with quite a few manufacturers. Mineral oils are still around as some engines call for their application. There's also blended Synthetic and Mineral oil, should your engine need it.
What about additives?
As far as oil additives go, you can buy your engine oil with them already integrated or as a separate concentrate, which you'll add to your oil. To name a few, such additives can be MoS2 (Molybdenum Disulfide), which companies like Liqui Moly use, for example, as it's posed to reduce friction and wear in harsher conditions. Another one would be Castrol's Dualock technology, which, simply put, promotes the engine oil to cling to engine components, particularly in situations like starting your car in the morning where lubrication on those components is minimal and significant wear can happen. Some would regard additives to be either snake oil or completely unnecessary. Still, in some instances and with independent testing, they have been proven to work but are not the miracle cures for your engine.
So, what is the best oil?
The manufacturer recommends the best oil for your car. Remember, the manufacturer spent copious amounts of money in research and development to design an engine that functions around a particular grade and style of oil. Such information can be found in your car's user manual. However, that can change when you've modified your engine or your engine is high mileage. In the instance of modification, see what a qualified specialist recommends. In a high mileage engine, you can go slightly thicker than the manufacturer recommended, but ideally, use what's always been recommended in the car. Additives are acceptable but, in our opinion, aren't necessary. However, using them won't hurt.
If your engine has been maintained accordingly, you shouldn't have to deviate. Make sure you change your oil and oil filter at the specified service interval or earlier.
