The Ins and Outs of Engine Oil Labelling

Automotive engine oils are a special class of petroleum products, whose quality level and manufacturing process are governed by state standard GOST 17479.1-85. This document also sets out how products are to be labelled.

The letter “M” at the very start indicates that the oil belongs to the engine class. The labelling also reflects indicators such as:

• the type of engine the oil is intended for; • how highly boosted the engine is; • the list of operating conditions.

Oils are accordingly divided into groups. If you see the letter “A” on the label, the product is intended for non-boosted engines. Lightly, moderately, and heavily boosted engines call for oils labelled “B,” “V,” and “G” respectively. Two further letters are also used: “D” for heavily boosted engines running on diesel fuel under the harshest conditions, and “E” for slow-running diesel engines running on fuel containing up to three and a half percent sulphur — machines in this category include asphalt pavers and construction equipment used in building housing developments or renovating hotels in Moscow.

When an engine runs strictly on petrol, its type is marked with the index “1,” while diesel engines get the index “2.” If an oil can be used in both cases, the engine index is left out of the labelling.

Adding additives to lubricants improves the properties needed for machinery operating under demanding conditions. The letter “I” indicates that the oil contains imported additives.

Group “B” oils are best used for petrol engines running under medium-duty conditions. Where loads are higher, category “G” oils should be preferred.

If the letter “Z” appears on an oil's label, it indicates the presence of thickeners. They're used to raise the oil's viscosity so it can be used year-round. In other words, it acts as an all-season oil. In that case a viscosity grade must also be stated.

These are the main secrets behind the labelling printed on oil.