Auto parts and accessories store shelves will be crammed with containers of engine oil from different manufacturers.

Their labels could be more confusing than enlightening, unless you understand some of the codes used and can relate it to your vehicle’s requirements.

Start by checking your vehicle owner’s handbook for the manufacturer’s recommendation for viscosity (some manuals give a temperature chart to allow selection of the correct viscosity for the prevailing climatic conditions) and required minimum service rating.

The oil you use must meet both specifications – using the wrong oil can adversely affect engine operation, fuel economy and engine durability.

SAE ratings define viscosity, and in simple terms the higher the number the ‘thicker’ the oil at a specified temperature.

This label shows a 10W-40 multigrade oil – 10W shows it acts like a ‘thin’ oil when cold (the W = winter) and the 40 like a ‘heavier’ oil when hot.

There are different service rating systems – API, ACEA, ILSAC are the most common.

Some Japanese engines specify a JASO rated oil.

The above sample shows both SAE (SN/CF) and ACEA (A3/B4) ratings. ILSAC ratings would be denoted by a GF prefix and number e.g. GF3 or GF4.

A vehicle manufacturer may also require an oil meeting their own technical specifications – this should be shown in your handbook, if applicable.

Look for a reputable brand oil that exactly matches all your vehicle’s requirements.

If you can’t find one, then you should consult with your dealer or one of the major lubricant maker’s technical help lines for a suitable alternative.