What is the highest grade model for diesel engine oil?
3 Answers
The highest grade for diesel engine oil is CJ-4. The grades of diesel engine oil are roughly categorized as: CA, CB, CC, CD, CE, CF, CF-4, CG-4, CH-4, CI-4, CJ-4. Different models of diesel engine oil grades indicate varying oil grade levels and corresponding applicable vehicle types, meaning the further the letters are in the sequence, the higher the oil quality grade, and so on. API engine oils are divided into two categories: "S" series: The "S" series represents oils for gasoline engines, with specifications including: API SA, SB, SC, SD, SE, SF, SG, SH, SJ, SL, SM, SN. "C" series: The "C" series represents oils for diesel engines. When both "S" and "C" letters are present, it indicates that the oil is suitable for both gasoline and diesel engines. The SN grade is currently the highest grade of oil. SJ was the standard in the 1990s, SL was the standard in 2001, SM was the standard in 2004, and SN was the standard in 2010.
Speaking of the highest grade of diesel engine oil, I know the current standard is API CK-4, which is the latest specification from the American Petroleum Institute. Over the years of running a repair shop, I've seen many vehicle owners using lower-grade oils leading to engine wear issues. CK-4 can meet modern emission requirements, reduce carbon deposits, and protect component lifespan. During routine maintenance, I recommend choosing it with a synthetic formula and checking the oil quality every 10,000 kilometers, especially for heavy-duty trucks or vehicles with long working hours. After switching to higher-grade oil, the failure rate of customers has dropped by more than half, saving both hassle and money. Ignoring this standard may lead to stuck piston rings or cylinder wall scratches over time, resulting in higher repair costs. When choosing a brand, don't go for cheap options—only reputable brands can provide assurance.
For frequent long-distance road trips, choosing API CK-4 diesel engine oil is the right move. Last time I drove to the northwest, after switching to it in my pickup truck, the fuel consumption stabilized, saving fuel and extending component lifespan. This standard represents the industry's top-tier, compatible with modern engine emission controls. In daily driving, using high-grade engine oil ensures smooth operation and reduces the risk of sudden breakdowns. I also regularly check the oil dipstick for dirtiness—timely oil changes are crucial. Based on my long-distance experience, opting for premium CK-4 oil brings peace of mind; don’t invite trouble by skimping on cost. In the safety-first driving philosophy, engine oil quality should never be compromised.
