Most People: “Oil. It goes into the car. Lubricates things. Everything works.”
Yep, you’d think it would really be that simple, but when you’re faced with making a decision on what the best type of oil to put in your car (it will happen, someday), you’re stumped. Full synthetic oil, semi synthetic oil, mineral oil - it is understandably confusing and can be difficult to know the difference but it is actually quite simple. Read on, and we’ll give you the full lowdown.
Synthetic oil is basically oil that has been enhanced by scientists. It has been developed to work over a wide range of temperatures and conditions, while reducing drag on the engine to help reduce fuel consumption. It also actively cleans the engine's internals as it’s pumped around. Synthetic oil is made from a base oil, powder additives, and a carrier oil that enforces an even distribution of the additives.
Almost all synthetic oils start with highly refined crude oil, pumped from deep underground, and that’s exactly the same source as conventional mineral oil. The primary difference between synthetic oil and traditional mineral oil is how much it has been refined. These days, all grades of oil are manufactured with additives that increase performance in some shape or form. Refinement processes have enabled enhancements that can lower friction, reduce engine sludge, and increase performance. Synthetic oil has been refined for use in jet engines, high-performance vehicles, as well as everyday vehicles.
Fully Synthetic Oil
Fully synthetic oil is considered to be the purest and cleanest form of synthetic oil. It is important to note that there is no grading standard for synthetic oils, and the makeup of a Fully Synthetic oil can vary by manufacturer...which basically means that the term “Fully Synthetic” is essentially just a promotional headline! Fully synthetic oils are often required in newer vehicles with turbocharged engines as these operate at much higher temperatures than standard engines.
Semi-Synthetic Oil or Synthetic Blends
Semi-synthetic oils (also called synthetic blends of oil) are a mixture of mineral oil and synthetic oil, which are engineered to have many of the benefits of full synthetic oil but without the price tag. However, the impurities of mineral oil are still contained in the blend. Synthetic blends are cheaper than fully synthetic motor oils but they’re a higher performance oil than traditional engine oil.
Synthetic Oil VS Mineral Oil
They may look exactly the same, but there’s two major differences between synthetic and traditional, mineral or multigrade oil.
How they’re made
Refinement is the key here - synthetic oil passes through many more levels of refinement than mineral oil. Mineral oil is simply not refined to perform at the same level as synthetic oil.
How they perform in your engine
When comparing the performance of synthetic oil against mineral oil in your engine, they’re worlds apart. Given the same amount of usage, mineral oil will be thicker and sludgy compared to synthetic oil. Synthetic oil protects the engine due to lower levels of friction. Additives help clean the engine of deposits. And, fewer impurities mean it burns cleaner, thickens far more slowly, and has fewer deposits to start.
A nasty case of engine sludge built up.
Benefits of Synthetic Oil VS Mineral Oil
- Fewer emissions
- Better fuel and oil economy
- Increased engine protection and wear from lower friction
- Longer intervals between oil changes
- Reduced engine drag from greater resistance to thickening
- Oil quality is more predictable and uniform
- Better all-weather protection
- Quicker engine start time
- Helps clean engine sludge and deposits
Oil Change Intervals
Synthetic oils are less susceptible to break down which means that they do not need to be changed as often as conventional oils. The more resilient properties of synthetic oil also mean that your engine is protected better through the whole service periods. Synthetic oil change intervals range 10,000-15,000 miles or once a year (whatever comes first). That extra 5,000 miles may be worth the investment.
Synthethic Oil VS Mineral Oil - What’s The Difference To Drivers?
- You’ll have better fuel efficiency with Synthetic oil, but it might not be enough to notice it in your pocket.
- Your engine will be better protected with synthetic oil, which should save you money in the long run.
- Full synthetic oil will cost you the most to use.
- You should have longer oil change intervals with synthetic oil.
- Your engine will have less deposits
What Is the Best Oil To Use?
There is no “bad” oil, just some key differences in how they perform in your engine. The general belief is that Fully Synthetic is the best engine oil, because it is marketed as being the cleanest, most refined oil. Note - there aren’t any industry grading standards in place for full synthetic oil. Semi-synthetic oil is widely believed to be better than mineral oil, and cheaper than full synthetic.
Can I Switch Between Mineral And Synthetic Oil?
Yes, but make sure to stick to the oil grade that your car manufacturer recommends (e.g. 5W-30). If you decide to swap from an inferior oil to using synthetic oil, change the oil filter at the same time because this catches nasty debris before it's circulated to the rest of the engine. Synthetic oils typically provide better protection than conventional oils, but switching back and forth between full synthetic and mineral oil will not damage the engine. However this will depend on the engine being in a good quality state.
Can You Mix Engine Oils?
As a general rule of thumb, it’s not recommended to mix different oils. However, nothing detrimental will occur if you mix synthetic oil with either semi-synthetic or mineral oil. If this was your only option, mixing oils would be better than running out of oil and potentially causing damage to your engine. Mixing oils will reduce your oils ability to perform at its best and it may not last as long as it would have normally.
Engine Oil For My Car
There’s 2 ways to find the recommended engine oil for your car.
Use an engine oil selector - try MicksGarage.com’s oil lookup. Just enter your vehicle make, model and year, and we’ll show you the oil that is recommended for your car.
Check your owners manual under the engine oil section. This will tell you the exact grade, e.g. 10W-40, or BMW Longlife-01 and the specification, e.g. A3/B4 that you need to ensure is met. Then you know that you’re looking for an oil that matches this grade.
What Is The Best Brand Of Oil To Use?
The most popular brands of engine oil on the market today are Castrol, Total, Mobil, Millers, Comma. We recommend Kast oil as a highly cost-effective alternative brand.