The European Automobile Manufacturers’ Association, (ACEA) sets benchmarks for oil performance, known as ACEA Oil Sequences. Updated every four years, with the latest (E8 & E11) in 2022, these guidelines categorise heavy-duty engine oils with an “E” prefix. Each category underlines specific properties and applications, crucial for making informed decisions about engine oil.

We will look at these categories below:

E4

Considered “stable” the key characteristic of E4 oils is their emphasis on a high level of detergency, reducing the build-up of combustion deposits on pistons and excellent control of cleanliness. Although they are not low-SAPS oils and are not recommended for vehicles with DPF, E4 products usually have either partially- or fully-synthetic oil or at least, the very highest-rated (group III) mineral oils. For this reason, E4 oils would be more expensive than your regular mineral based formulations.

E6

Ultra-high-performance diesel lubricants (UHPD), E6 lubricants are specifically designed for use in long drain applications operating in severe conditions. Very similar to E4 engine oils, E6 has the extra benefit of low-SAPS for vehicles that have a DPF and are usually fully synthetic. They are considered top-performing oils but are usually the most expensive type of engine oil. Many of these oils can also provide fuel economy benefits. E6 spec has now been replaced with E8. 

E7

An oil that suits the majority of current engines as long as they do not have a diesel particulate filter (DPF) in their exhaust. Usually a mineral based engine oil they would be cheaper than low-saps oils. These factors make it one of the most popular sequences in the Irish market today.

E9

These oils are extremely similar in application to E7 oils, but with one important exception – they have tight limits for sulphated ash, phosphorus and sulphur. They are considered low-SAPS oils and are designed specifically to suit trucks that are built with a DPF in the exhaust: low-SAPS oils produce less ash when they burn, so the DPF needs cleaning less frequently.  Although still mineral-based, E9 oils need a low-sulphur base oil that differs from the group I base oil used for E7 oils, which would make E9 more expensive than E7. These were recently replaced with the new E11 spec.

E8 

ACEA E8 oil category sets high standards for motor oils, requiring them to maintain consistent performance, keep engines clean, and effectively manage soot and contaminants. Oils in this category are designed to offer outstanding anti-wear protection and maintain their stability throughout the entire oil change interval. Specifically formulated for EURO VI engines, E8 oils are also compatible with older EURO models (I through V), supporting extended drain intervals. It’s crucial to adhere to the manufacturer’s recommended oil change schedules.

E11 

Building on the E9 standard, this high viscosity-index category prioritises piston cleanliness and imposes stringent limits on factors contributing to bore polishing. The specification is focused on minimising wear, managing soot effectively, and neutralising contaminants. Oils conforming to this standard are optimised for diesel engines in demanding heavy-duty environments. They are compatible with EURO VI engines and maintain backward compatibility with EURO V through EURO I engines, promoting extended drain intervals.