With the same viscosity grade, European standard engine oils in the ACEA C series can often directly substitute those in the A/B series, but there are prerequisites and considerations to note. Conversely, A/B series oils must never be used to replace C series oils.

Core Prerequisites and Key Points

Key differences: The A/B series are high-SAPS (sulfur/phosphorus/ash) and high-TBN (total base number) oils, focusing on long-term protection. The C series are mid- to low-SAPS, low-ash oils designed to be compatible with aftertreatment systems such as GPF/DPF, offering environmental benefits but with lower TBN.

Compatibility Conditions

A/B series oils are only suitable for China V and earlier vehicles without GPF/DPF (China VI vehicles with aftertreatment systems must use C series oils).

The viscosity grade must be identical, and key parameters such as HTHS must match (e.g., A3/B4 corresponds to C3, A5/B5 corresponds to C2).

Absolute prohibition: A/B series oils must never be used as substitutes for C series oils. Doing so may clog the GPF/DPF or damage the three-way catalytic converter.

When to Exercise Caution or Avoid Substitution?

For some very old classic models or specific engines: In rare cases, older engine designs might rely on a certain level of ash in the oil to provide sealing (for heavily worn engines) or specific anti-wear properties. However, such cases are uncommon, and the vehicle’s specific instructions should be consulted.

Viscosity matching is a prerequisite: Substitution must be performed under the same or manufacturer-recommended viscosity grades. For example, a 5W-40 C3 oil cannot replace a manufacturer-recommended 0W-20 A5/B5 oil, even if the performance level is higher.

Kroneseder Lubricants K8 Series fully synthetic engine oil is formulated with advanced fully synthetic base oils and high-performance imported additives. It delivers strong and resilient oil film strength under both high and low temperatures. The oil’s performance is significantly enhanced, offering extended drain intervals, energy savings, and environmental protection. It is suitable for modern high-end luxury gasoline engines, turbocharged engines, including those compliant with Euro VI low-emission standards, and gas-fueled engines. It provides excellent protection for engines and delivers a high-quality driving experience.