All motor engines need a good lubricant to keep their components moving and prevent them from seizing.

Engines are incredibly hard working and they have to be exceptionally durable, so it makes sense to ensure that any oil you put into your car is the best quality you can afford.

Superior oil will help to keep the engine clean, which will help to keep you safely on the road for longer.

However, if you have ever looked at the shelves of a car accessories shop, you’ll discover a dizzying array of engine oils to choose from. But which one is the right specification for your vehicle?

It’s absolutely vital to choose the right grade of engine oil if you have to top up between services, so check your vehicle maintenance book because it should tell you exactly what to buy.

Here at, we’ve pulled together the top things you should be looking out for when standing at the shelves. 


All engine oils are graded according to their viscosity (thickness). Modern oils tend to be thinner, which means they can circulate round the engine quickly after the ignition key is turned. Thinner oils also help to maximise fuel consumption.

Most engine oils nowadays are multi-grade, which means that they are suitable for both winter and summer. You’ll notice that two grades are marked on the container, eg: 10W-40, 5W-30. The first one refers to the cold temperature grade (W stands for ‘winter’) and the lower that number is, the better performance it has for a cold start.

The second number refers to high temperature grade and the viscosity levels that it has to achieve at 100C. A 10W-30 oil will thin out faster than a 10W-40 oil.

Synthetic oil

Some car manufacturers recommend synthetic oils, particularly for high-tech engines. Synthetic oils are refined and purified to remove more impurities, thereby enabling a superior performance, better flow at low temperatures and peak performance at high temperatures. They also protect the car’s engine.

However, they are more expensive. If your car manufacturer recommends a synthetic oil, it is worth the investment. However, if you vehicle does not need synthetic oil, the extra cost might not be worth it.

Synthetic-blend oil

Synthetic blend oils are compatible with conventional oils, which means it is easy to switch between the two without damaging your vehicle’s performance. They provide greater engine protection and hold their viscosity in cold temperatures, too, making it a good option for many cars.


Tests and performance standards led to the introduction of specifications, which make sure that engine oils are compatible with the latest technology.

Your vehicle handbook will provide the information you need to ensure you select the specification that is right for your car engine, e.g. the CCMC/ACEA (European Constructors), the American Petroleum Institute (API), ILSAC (The International Lubricant Standardisation and Approval Committee) or JATO (the Japanese Automotive Standards Organisation). 

Make sure you choose oil that is recommended by the manufacturer but if you cannot find the correct one, contact the parts department of the manufacturer’s dealer.

Sarah Lewis


May 15, 2015