What is API SJ engine oil?
2 Answers
In the engine oil industry, oil grades are classified based on quality levels, with the quality classification following the standards set by API (American Petroleum Institute). The API standard is the most authoritative classification system for engine oil quality in the industry, where quality grades are represented by a combination of two letters. More details about the API quality classification are as follows: 1. The "S" series represents oils for gasoline engines: specifications include SA, SB, SC, SD, SE, SF, SG, SH, SJ, SL, SM, SN. 2. The "C" series represents oils for diesel engines: specifications include CA, CB, CC, CD, CE, CF, CF-2, CF-4, CG-4, CH-4, CI-4. 3. When both "S" and "C" letters are present: it indicates that the oil is suitable for both gasoline and diesel engines. From "SA" up to "SN," each subsequent letter indicates better performance than the previous one, with letters further in the alphabet representing higher quality grades, making the engine oil more effective. Among international brands, most engine oils are of SF grade or higher.
API SJ oil is a gasoline engine oil specification certified by the American Petroleum Institute, primarily used in older vehicles from the late 1990s to the early 2000s. I remember when I bought my first car and noticed the label said SJ, I was curious and looked it up. It provides basic anti-wear and cleaning protection, but it falls short compared to newer standards like SN or SP. Modern engines are more precise, with high compression ratios and turbocharging, requiring oils like SN or SP to enhance performance and longevity. If you drive an older model, like some classic Toyotas or Hondas, SJ oil might still work, but regular oil changes are crucial—otherwise, engine wear accelerates, sludge builds up, and noise increases. I recommend upgrading to newer oil grades. After all, changing an oil filter isn’t expensive, so don’t cut corners and risk bigger costs. Always check the manual for recommended specifications during maintenance for peace of mind.
