ACEA Engine Service Classification

A/B: PETROL AND DIESEL ENGINE OILS
DESCRIPTION
A1/B1 Stable, stay-in-grade oil intended for use at extended drain intervals in gasoline engines, and car and light van diesel engines specifically designed to be capable of using low friction low viscosity oils with a high-temperature/high‑shear rate viscosity of 2.6 mPa.s for xW/20 and 2.9 to 3.5 mPa.s for all other viscosity grades. These oils are unsuitable for use in some engines. Consult owner manual or handbook if in doubt.
A3/B3 Stable, stay-in-grade oil intended for use in high-performance petrol, and car and light van diesel engines and/or for extended drain intervals where specified by the engine manufacturer, and/or for year-round use of low viscosity oils, and/or for severe operating conditions as defined by the engine manufacturer.
A3/B4 Stable, stay-in-grade oil intended for use in high-performance petrol and direct injection diesel engines, but also suitable for applications described under A3/B3.
A5/B5 Stable, stay-in-grade oil intended for use at extended drain intervals in high-performance petrol, and car and light van diesel engines designed to be capable of using low friction low viscosity oils with a high-temperature/high‑shear rate viscosity of 2.9 to 3.5 mPa.s. These oils may be unsuitable for use in some engines. Consult owner manual or handbook if in doubt.
C: CATALYST COMPATIBILITY OILS
DESCRIPTION
C1 Stable, stay-in-grade oil intended for use as catalyst compatible oil in vehicles with DPF and TWC in high‑performance car and light van diesel and petrol engines requiring low friction, low viscosity, low SAPS oils with a minimum HTHS viscosity of 2.9 mPa.s. These oils will increase the DPF and TWC life and maintain the vehicle’s fuel economy. Warning: these oils have the lowest SAPS limits and may be unsuitable for use in some engines. Consult owner manual or handbook if in doubt.
C2 Stable, stay-in-grade oil intended for use as catalyst compatible oil in vehicles with DPF and TWC in high‑performance car and light van diesel and petrol engines designed to be capable of using low friction, low viscosity oils with a minimum HTHS viscosity of 2.9 mPa.s. These oils will increase the DPF and TWC life and maintain the vehicle’s fuel economy. Warning: these oils may be unsuitable for use in some engines. Consult owner manual or handbook if in doubt.
C3 Stable, stay-in-grade oil intended for use as catalyst compatible oil in vehicles with DPF and TWC in high‑performance car and light van diesel and petrol engines, with a minimum HTHS viscosity of 3.5 mPa.s. These oils will increase the DPF and TWC life. Warning: these oils may be unsuitable for use in some engines. Consult owner manual or handbook if in doubt.
C4 Stable, stay-in-grade oil intended for use as catalyst compatible oil in vehicles with DPF and TWC in high‑performance car and light van diesel and petrol engines requiring low SAPS oil with a minimum HTHS viscosity of 3.5 mPa.s. These oils will increase the DPF and TWC life. Warning: these oils may be unsuitable for use in some engines. Consult owner manual or handbook if in doubt.

SAPS: Sulfated Ash, Phosphorus, Sulfur.
DPF: Diesel Particulate Filter.
TWC: Three-Way Catalyst.
HTHS: High-Temperature/High‑Shear Rate Viscosity.

E: HEAVY-DUTY DIESEL ENGINE OILS
DESCRIPTION
E4 Stable, stay-in-grade oil providing excellent control of piston cleanliness, wear, soot handling and lubricant stability. It is recommended for highly rated diesel engines meeting Euro I, Euro II, Euro III, Euro IV and Euro V emission requirements and running under very severe conditions, e.g. significantly extended oil drain intervals according to the manufacturer’s recommendations. It is suitable for engines without particulate filters, and for some EGR engines and some engines fitted with SCR NOx reduction systems. However, recommendations may differ between engine manufacturers so driver manuals and/or dealers should be consulted if in doubt.
E6 Stable, stay-in-grade oil providing excellent control of piston cleanliness, wear, soot handling and lubricant stability. It is recommended for highly rated diesel engines meeting Euro I, Euro II, Euro III, Euro IV, Euro V and Euro VI emission requirements and running under very severe conditions, e.g. significantly extended oil drain intervals according to the manufacturer’s recommendations. It is suitable for EGR engines, with or without particulate filters, and for engines fitted with SCR NOx reduction systems. E6 quality is strongly recommended for engines fitted with particulate filters and is designed for use in combination with low sulfur diesel fuel (max 50 ppm). However, recommendations may differ between engine manufacturers so driver manuals and/or dealers should be consulted if in doubt.
E7 Stable, stay-in-grade oil providing effective control with respect to piston cleanliness and bore polishing. It further provides excellent wear and turbocharger deposit control, soot handling and lubricant stability. It is recommended for highly rated diesel engines meeting Euro I, Euro II, Euro III, Euro IV and Euro V emission requirements and running under severe conditions, e.g. extended oil drain intervals according to the manufacturer’s recommendations. It is suitable for engines without particulate filters, and for most EGR engines and most engines fitted with SCR NOx reduction systems. However, recommendations may differ between engine manufacturers so driver manuals and/or dealers should be consulted if in doubt.
E9 Stable, stay-in-grade oil providing effective control with respect to piston cleanliness and bore polishing. It further provides excellent wear control, soot handling and lubricant stability. It is recommended for highly rated diesel engines meeting Euro I, Euro II, Euro III, Euro IV, Euro V and Euro VI emission requirements and running under severe conditions, e.g. extended oil drain intervals according to the manufacturer’s recommendations. It is suitable for engines with or without particulate filters, and for most EGR engines and for most engines fitted with SCR NOx reduction systems. E9 is strongly recommended for engines fitted with particulate filters and is designed for use in combination with low sulfur diesel fuel. However, recommendations may differ between engine manufacturers so driver manuals and/or dealers should be consulted if in doubt.

EGR: Exhaust Gas Recirculation.
SCR: Selective Catalytic Reduction.
NOx: Nitrogen Oxide.
More information is available at http://www.acea.be/images/uploads/files/2012_ACEA_Oil_Sequences.pdf