What is the Difference Between Engine Oils?
3 Answers
Here are the key differences regarding engine oils:1. Choose the Type: Currently, there are two main types of engine oils available on the market: mineral oil and synthetic oil. Synthetic oil can be further divided into semi-synthetic oil and full-synthetic oil. The difference between them is quite simple—it lies in the base oil. Mineral oil is refined directly from crude oil without any chemical changes or artificial additives, similar to 'all-natural, additive-free' beauty products for women. Semi-synthetic oil is artificially produced based on mineral oil, while full-synthetic oil is entirely synthesized through chemical methods—a purely man-made product that represents a higher-grade option. Interestingly, unlike beauty products, chemically synthesized engine oils are actually better.2. Choose the Performance: Next, let’s discuss the performance differences. Synthetic oil has better fluidity at low temperatures compared to mineral oil, preventing solidification or freezing, which aids in cold starts for vehicles. In terms of high-temperature resistance, synthetic oil also outperforms mineral oil, providing better protection for high-revving engines. Additionally, synthetic oil has lower volatility and a longer service life than mineral oil, making it more durable—except for engines that burn oil. Due to differences in manufacturing processes and costs, synthetic oil is also more expensive than mineral oil.
I've run an auto repair shop for over a decade and seen all types of motor oil differences. The most basic mineral oil is cheap but prone to carbon buildup, suitable for short-term use in older vehicles. Synthetic oil is more expensive but has stronger cleaning power and durability, easily lasting 10,000 km between changes. Semi-synthetic oil offers a balanced solution with good cost performance. There's also viscosity grading like the 0W-20 number combination - the smaller the number before W, the faster winter starts; larger summer numbers provide better protection. Different vehicles must select oil according to the manual - for example, turbocharged engines must use synthetic oil to prevent malfunctions. Random oil changes will shorten engine life! Regularly checking oil level discoloration is also crucial.
After using my car for several years, I realized there's a lot to consider when changing the oil. Mineral oil costs just over a hundred yuan per bottle, but it causes louder engine noise, requires frequent changes, and makes me worry about cooling issues on long trips. Synthetic oil costs a bit more, around two hundred yuan, but provides better lubrication, makes the engine run smoother, and has a longer change interval which saves money in the long run. Semi-synthetic oil is a practical middle ground. The key is to look at the API rating—higher grades like SM or SN offer better engine protection. Don't assume all oils are the same; I once used the wrong oil and saw a huge increase in fuel consumption. Later, I followed the vehicle manual for oil selection and felt much more at ease. Ambient temperature also matters—in hot southern climates, higher viscosity oil is needed to prevent overheating.
