Here's our guide to car oils, simplifying the complicated topic of different oils and helping you to choose the best oil for your vehicle.
There are two types of oil, conventional oils and synthetic oils. Synthetic oils are man-made lubricants specifically designed for a purpose. All modern vehicles use synthetic oils as they provide many benefits over conventional oil, including reducing sludge and deposit build ups, greater protection against engine wear, protection against high temperatures and controlling oil breakdown. As such, the below guide focuses on synthetic oils.
All oils have a viscosity level, which relates to the numbers on the oil such as 5W-30. Viscosity is the resistance of a liquid to change in shape. For example, water would have a very low viscosity as when you pour it into a glass it takes the shape of the glass quickly. Compare this to syrup, pour syrup into a glass and it’ll slowly take the shape of the glass meaning it has a high viscosity. An easier way to think of viscosity is the thickness of a fluid.
Manufacturers build their vehicle engines with a certain oil viscosity in mind e.g. 5W-30. The “W” stands for Winter, with the numbers before the “W” relating to the viscosity in colder temperatures. The numbers after the W relate to the viscosity in warmer temperatures. For example, a 5W-30 oil would flow better in colder weather than a 15W-30.
Using the correct viscosity of oil, which is usually in the vehicle handbook, is important. Using a higher viscosity oil can cause excessive mechanical wear in the engine and shortened engine life. Using a lower viscosity oil can reduce fuel economy, result in higher engine loads, and eventually shorten the life of the engine.
To complicate things slightly further, oils not only vary in viscosity, but they also vary in specification. This is because oil producers add additives to the oil to ensure they meets the demands of modern engines. The ACEA break oils down into classes and categories which look like C1 or B2. The letter is the class of oil, while the number relates to the category within the class. These are known as the “ACEA Oil Sequences”. Vehicle manufacturers also build and test their engines to work with a certain ACEA Oil Sequence which must be used to prevent engine damage.
There are many oil brands out there producing synthetic oils for vehicles. Some you may have heard of, while others you may not have. Castrol, Shell, Mobil, Liqui Molly, Motul, Elf, Comma, Valvoline are some of the most common and best-known vehicle oil producers in the world. Not all oils are equal despite having the same viscosity and ACEA Oil Sequence. The bigger, well-known brands will often meet and exceed the oil specifications set out by the ACEA providing more protection for the engine, leading to a longer engine life. Smaller budget manufacturers will only just meet specifications to keep costs down.
Here are Quest Motor Group we’ll ensure the oil we put into your vehicle is the correct viscosity, as well as the correct oil specification as set out by the manufacturer of your vehicle. We use the well know Castrol oils as standard which often exceed the ACEA’s specifications, ensuring your vehicle’s oil will keep your engine protected and running smoothly until its next service is due. Click the button below to book your oil and filter change from just £99 at Quest Motor Group in Braintree, Essex!