Synthetic vs Semi-Synthetic vs Mineral motor oil – What's best for your car?

Oil is a very important fluid for your car. Without it, your engine won’t survive a few minutes without seizing up and breaking. If you run your car with the wrong kind of oil, you could also cause substantial damage to your engine. 

So what oil do you use? Oil weights are different, and there is a specific weight that you need to use for a specific type of oil. As part of proper vehicle maintenance, your manual will tell you what weight you need to use if you are opting for mineral, synthetic, or semi-synthetic, otherwise known as blended. Which oil, however, is the best oil to use? Mineral oil is the most affordable, so why not go with that all the time? Or the happy medium, which is semi-synthetic? It’s not as simple as it seems so let’s go over a few points for consideration when deciding on your next bottle of oil.

Like what we said in the intro, mineral oil is the most affordable oil that you can get and it’s a cost-effective way to get through your service interval. Also, if you are running an older car, mineral oil can be ideal or even recommended by the manufacturer. This is because these types of oils tend to be thicker to avoid thinning out when under a lot of heat. Under normal driving conditions, the fluid is thicker and fills out the perhaps worn-down tolerances of your car’s older engine. If your car is also older or much older, it is also likely that synthetic oils weren’t commonplace just yet, hence mineral could be the best choice in select circumstances. 

However, the downside of using mineral oil is that you will need frequent oil changes. Mineral oil breaks down easier than synthetic or even semi-synthetic oils. Among the three types, it has the most impurities, it’s the least durable, and it is more prone to thinning at higher temperatures, and to counteract this, new oil must be fed regularly to avoid damaging the engine. For most cars in the Philippines, expect to change your oil around every 3,000 kilometers more or less depending on your car and depending on your service manual or service center. You also have to run a thicker oil, which means that you might feel your engine get a bit more sluggish.

The best of both worlds, in terms of cost and performance, is semi-synthetic. As its name suggests, it’s a blend that is essentially mineral oil with synthetic elements that boost the efficacy and durability of the oil to provide better performance and longevity over standard mineral oil. This type of oil lasts a bit longer, lasting around 5,000 km or more and a longer duration before needing a change depending on your service manual. Semi-synthetic is also purer than mineral since it is a blend and not just regular oil. On average, you can also expect a slightly thinner weight, and because there are synthetic elements in the oil, it’ll be more resistant to heat. 

The downside to this oil is that it is a bit more expensive, and you are still dealing with some mineral oil content, which means that you will still be running a relatively thick oil, and your oil will be more susceptible to breaking down easier than synthetic oils, but less prone compared to standard mineral oil. It’s a nice happy medium for your car if you are on a budget. It will last reasonably long and will give you good service. 

The best type of oil in the business is synthetic, bar none. Science and technology have allowed us to engineer our cars better and also engineer fluids down to the molecule. Look at it this way, mineral oil was tweaked as much as it could be with a few additives and such to shoehorn into a particular use case. However, synthetic oils were built from the ground up and not shoehorned into anything, in other words, it was made for the job. Performance-wise, your engine is better-protected against high-stress situations like driving all out on the race track. 

Evidently, the biggest benefit that you get with a fully-synthetic oil is that the manufacturer engineered the oil to give the best possible performance which means that the oil is formulated and engineered to be consistently heat resistant, not to thin out when under high temperatures, and to provide the necessary lubrication and protection without weighing the engine down. If you notice, when you go for a fully-synthetic oil, the manufacturer recommended viscosity is much thinner than what you can typically get in a mineral or synthetic. This is because the viscosity of the oil can remain more consistent through a myriad of engine temperatures. This allows the engine to move easier since there is less oil that is weighing the engine components down, which results in slightly improved performance in response and even in fuel economy. On top of all of that, you won’t need to change your oil frequently in general. You also get the luxury of choice. There are specialist oils that are specifically designed and formulated for performance driving or general use. A lot of manufacturers now recommend fully-synthetic oils because of the consistency that the lubricant offers. 

However, due to the work that has gone into making the fluid as good as it can be, synthetic oil is the most expensive type of engine oil available, generally speaking. Expect it to cost nearly – if not over double – the price of mineral or semi-synthetic oil. If you drive normally anyway, you may not be able to reap all the benefits of going fully-synthetic, however, you cannot deny the benefits of having a lot of headroom when it comes to one of the most important parts of your car.