What type of oil should be used for Cummins engines?
3 Answers
Here is an introduction to the oil types used for Cummins engines: Environment above -5°C: When the ambient temperature is above -5°C, use 15W-40 CF4, CG4, CF4/SG, or CG4/SH grade oil. Environment below -5°C: When the ambient temperature is below -5°C, use 10W-30 CF4, CG4, CF4/SG, or CG4/SH grade oil. For B and C series engines, CF4/SG or CG4/SH grade oil must be used. "Blue Supreme" oil: Cummins recommends using "Blue Supreme" oil. This brand of oil has a viscosity index of 15W-40 and a performance grade of CG4/SH. The additive formulation is specifically designed according to the unique performance characteristics of Cummins engines, effectively extending the oil change interval and reducing oil consumption rate.
I've driven Cummins heavy-duty trucks for over a decade, consistently using multi-grade 15W-40 oil that performs well in both hot and cold weather. The key is to use diesel-specific engine oil - CJ-4 and CK-4 grades are the safest bets, offering excellent anti-wear and cleaning properties. In Northeast China where temperatures drop to -20°C, I switch to 10W-30 for easier cold starts. Don't neglect oil change intervals - for long-haul heavy loads, change at 40,000 km, while light loads can stretch to 60,000 km. Pay attention to engine models too; for example, ISX series pairs better with CK-4, while older models can use CI-4. I stick to Shell Rimula or Mobil Delvac brands, but beware of counterfeits - always buy from authorized channels. Remember to change the oil filter simultaneously, as skipping it cuts the oil change effectiveness in half.
With 20 years of truck repair experience, Cummins engine oil selection depends on specific models. New China VI engines must use low-ash CK-4 oil to avoid DPF particulate filter clogging. For older China IV/V models, CJ-4 oil is sufficient and cost-effective. Recommended viscosity is 15W-40, but 10W-40 performs better in high-altitude areas to prevent high-temperature viscosity loss. Always inspect the oil pan for metal debris during oil changes - if found, check for bearing wear. Avoid inferior oil at all costs; I've seen too many engines fail due to oil coking and cylinder scoring. Oil sample testing every 500 hours or 20,000 km is far more reliable than guesswork.