What is No. 30 Engine Oil?
3 Answers
Mechanical oil grades are determined based on their kinematic viscosity at 50°C. The kinematic viscosity of No. 30 mechanical oil at 50°C ranges from 27 to 33 mm²/s, with a pour point of -10°C and a flash point of 180°C. Mechanical oils are categorized into seven grades from 10 to 70, with higher numbers indicating greater viscosity. The SAE lubricant viscosity classification for summer oils includes grades 20, 30, 40, and 50, where higher numbers denote higher viscosity and suitability for higher maximum temperatures. Below are specific details about engine oil: 1. Mineral Oil: Derived from crude oil, mineral oil is typically low-cost but oxidizes more easily due to its mineral base. Various imported additives are included, and its service life is approximately six months. 2. Semi-Synthetic Oil: Although more expensive to refine, it offers excellent oxidation resistance, making it a high-quality long-lasting oil with a service life of about twelve months. Considering the balance between price and quality, semi-synthetic oil has the widest range of applications. 3. Full Synthetic Oil: This is chemically synthesized oil that can maintain lubrication even when the base oil deteriorates.
SAE 30 oil is actually a type of single-grade oil, labeled with the SAE 30 viscosity grade, meaning its fluidity remains within a specific range at 100°C high temperature. I often use it when repairing cars to handle some older models. This oil has higher viscosity, making it suitable for engine protection in high-temperature environments, such as reducing wear during long-distance driving in hot summers. However, most modern vehicles now use multi-grade oils like 5W-30, which can adapt to both cold starts and high-temperature operation, offering greater flexibility. If you drive an older car in tropical regions, you might consider using SAE 30 oil, but don’t forget to change it regularly—typically every 5,000 kilometers—to prevent premature engine aging or increased noise.
I remember the first time I used SAE 30 oil was in my old Toyota. It was a hot day, and the engine kept making squeaking noises. A friend recommended SAE 30 as a single-grade oil with higher viscosity that could provide better lubrication for the engine under high temperatures. I gave it a try, and it really worked—the engine became noticeably quieter after startup. Looking back now, it suits certain specific vehicle models or weather conditions, like older engines in hot regions, but don't expect it to perform well in winter—it thickens at low temperatures, making cold starts difficult. I recommend car owners regularly check the dipstick to monitor the oil's color and viscosity. If it turns black or becomes too thin, it's time for a change; otherwise, the engine could suffer damage.
