What is conventional engine oil?

[DelFrank]

Conventional engine oil generally refers to mineral oil, but currently most vehicles use semi-synthetic or higher-grade oils. Engine oil introduction: Engine oil is the lubricant for engines, which serves to lubricate the engine, reduce friction, assist in cooling, and minimize buffering effects. Engine oil composition: Engine oil consists of base oil and additives. The base oil is the main component of lubricating oil, determining its fundamental properties, while additives improve and compensate for any deficiencies in the base oil's performance. Using lubricating oil helps reduce wear on engine components and extends their service life. Engine oils in the market are categorized into synthetic oils and mineral oils, with synthetic oils further divided into full synthetic and semi-synthetic oils.

[VioletFitz]

After repairing cars for ten years, I've found that many car enthusiasts have misconceptions about conventional motor oil. Conventional oil typically refers to mineral oil, which is directly refined from crude oil and still contains some impurities. The biggest advantage of this oil is its affordability—an oil change, including labor, costs only around 100 to 200 yuan, making it particularly suitable for older vehicles. For example, an old Jetta with over 200,000 kilometers on the odometer may experience fewer oil leaks with mineral oil compared to full synthetic. However, its downside is poor high-temperature resistance; it tends to degrade after about 5,000 kilometers in the engine and must be replaced. If you own a turbocharged (T) vehicle or frequently drive on highways, it's genuinely not recommended to use this type of oil.

[SanClara]

As an average working-class car owner, I've always used conventional mineral oil for my daily commuter car. The yellow 5W-30 jugs sold in supermarkets cost just over 100 yuan for 4 liters, offering exceptional value for money. This type of motor oil is perfectly adequate for sub-100,000 yuan family cars, especially since I only drive 20-30 kilometers daily for commuting. I remember the technician at the dealership service center saying that naturally aspirated engines have no issues with mineral oil, as long as you change it every 5,000 kilometers on schedule. The only caution is to avoid using it in regions where winter temperatures drop below -20°C, as poor low-temperature fluidity might cause starting difficulties. My neighbor's Corolla has been running on mineral oil for eight years, and the engine remains remarkably quiet.

[LaFrank]

Conventional oil is essentially the entry-level mineral oil. It's like feeding your engine coarse grains—cheap and filling, but lacking in nutritional value. The refining process is relatively simple, resulting in uneven molecular sizes, which makes the oil film prone to breaking under high temperatures. If your car was purchased within the last five years, I'd recommend spending a bit more on semi-synthetic oil. It costs a few dozen yuan more but can last an extra 2,000 kilometers. Last time I helped a friend inspect their engine, I noticed that cars using mineral oil had significantly more carbon buildup in the valve cover compared to those using synthetic oil. However, when changing oil, remember to check the viscosity rating—5W-30 is the most hassle-free all-season option.

[DeJulia]

The mechanic recommends conventional mineral oil as particularly suitable for three types of vehicles: cars over ten years old, backup vehicles driven less than 5,000 kilometers annually, and delivery minivans. The short oil change interval of this type of oil actually becomes an advantage—it needs to be changed every six months, which helps prevent oil emulsification in vehicles that sit idle for long periods. Last time when servicing a customer's 2010 Buick Excelle, using mineral oil for seven consecutive years kept the engine in good working condition. Remember two key points: never exceed the mileage limit—it must be changed at most every 5,500 kilometers; and avoid aggressive driving, as insufficient oil film strength during rapid acceleration can cause abnormal wear on cylinder walls.

[MiaRose]

From the perspective of vehicle requirements, conventional oil is most suitable for low-compression engines. For example, the old Lavida 1.6L with its cast iron engine, which doesn't operate at high temperatures, can manage perfectly well with mineral oil. However, modern direct-injection turbocharged vehicles shouldn't skimp on this expense—mineral oil oxidizes quickly under high temperature and pressure. My brother's Civic once used mineral oil, and by just 3,000 kilometers, sludge appeared on the dipstick. When selecting oil, it's also important to check the API certification mark. A standard SN grade is sufficient, but if the vehicle manual specifies SP grade, don't compromise. Ultimately, it's about matching the oil to the engine's needs—just as a regular car might not run as smoothly on premium liquor as it would on a standard one.