OIL SPECIFICATIONS

WHAT IS WRITTEN ON YOUR OIL CONTAINER AND WHAT DOES IT MEAN?

THE BASICS:

All oils are intended for an application and in general are not interchangeable. You would not for example put automatic transmission oil into your engine.

VISCOSITY:

Most oils today re multi-grade which means they fall into two viscosity grades (IE: 10W40).

In a 10W40 for example the “10W” (W=Winter) simply means the oil must flow at a low temperature. The lower the “W” number the better the oils cold temperature performance.

The “40: in 10W40 simply means the oil must flow within certain limits at 100 degrees Celsius. Once again, the lower the number, the thinner the oil

SPECIFICATIONS:

Specifications are important as these indicate the performance of the oil and whether it has met or passed the latest tests. There are two specifications that you should look for on any oil. API (American Petroleum Institute) and ACEA (Association des Constructeurs Europeens d’Automobiles).

API – This rating splits oils into two categories:

S = Petrol (EG: SH, SJ, SL, SM)

C = Diesel (CF4, CG4, CH4, CI4, CJ4)

The latest petrol engine oil is SN rated. The latest diesel engine oil is CK rated.

ACEA – This is the European equivalent of API but is more specific in what the performance of the oil actually is.

A = Petrol

B = Diesel

C – Catalyst compatible or low SAPS (Sulphurated Ash, Phosphorous and Sulphur)

A1 Fuel economy petrol

A2 Standard performance level (now obsolete)

A3 High performance and/or extended drain

A4 Reserved for future use in certain direct injected engines

A5 Combines A1 fuel economy with A3 performance.

B1 Fuel economy diesel

B2 Standard performance level (now obsolete)

B3 High performance/and or extended drain

B4 For direct injection car diesel engines

B5 Combines B1 fuel economy with B3/B4 performance.

C1-04 Petrol and light duty diesel engines based on A5/B5-04 low SAPS

Two way catalyst compatible

C2-04 Petrol and light duty diesel engines based on A5/B5-04 mid SAPS

Two way catalyst compatible

C3-04 Petrol and light duty diesel engines based on A5/B5-04 mid SAPS

Two way catalyst compatible, high performance levels due to higher HTHS

Put simply, A3/B3, A5/B5 and C3 oils are better quality, stay in grade performance oils.

APPROVALS:

Many oils mention OEM’s (Original Equipment Manufacturers) on their labels. Oil companies send their oils to OEM’s for approval for their specific components (EG engine, transmission). It is important that the right oil is used for the application.