Whether it’s after a breakdown or when you notice a leak, at some point you may need to mix two types of engine oils to fix an issue with your car. But what impact does this have on the engine’s performance? And is it safe to do so? In this guide, we go into more detail about engine oils and how they affect your vehicle.
Unsure whether you can mix two different types of engine oils? Find out what happens below.
What Happens If You Mix Two Different Engine Oils?
Broadly speaking, mixing engine oils will not damage your vehicle’s engine. Although it’s worth noting that if you are thinking about doing so, it’s best to match the viscosity of both oils as closely as possible.
Engine oils are graded by viscosity and defined by the temperature at which they best operate. Thin oils tend to have a lower viscosity and are used to help engines start quickly during cold weather, whereas thick oils protect engines during high temperatures.
You’ll find the viscosity level labelled on the canister of the engine oil. It’s the left-hand number (usually 5W or 10W). If you’re unsure which oil is right for your car, bear in mind that the lower the number, the lower the viscosity of the oil and the better it will be for helping your engine start in cold weather.
What’s more, the number on the right indicates the weight of the oil in colder temperatures, as the ‘W’ stands for winter.
Can I Mix Engine Oil From Different Brands?
Most experts agree that mixing two brands of engine oil can be risky to your engine’s performance. That’s because different manufacturers will use various methods of production and special additives, which means there will be certain oils that include different physical properties.
That said, some mechanics argue that as long as the engine oil manufacturer is API certified, then it’s more than fine mixing two brands of oil. However, you should always check the label if you’re unsure.
On the occasion you do have to mix engine oils, it’s advised you undertake an oil change and as soon as possible to avoid any long-term damages to your car’s engine.
Can You Mix 5W-30 and 10W-30 Oil?
Yes, it is perfectly safe for you to mix 5W-30 and 10W-30 engine oils. Thanks to their close viscosity, mixing the two oils will have no damaging effect on the engine. It’s worth remembering that 10W-30 has more density than 5W-30, so make sure you pour an appropriate amount when mixing.
At CarParts4Less, you’ll find a wide range of industry leading engine oils that are specifically designed for your vehicle. Simply search for your registration number by using our ‘Find Car Parts’ tool, and we’ll provide you with a list of products that are suited to your precise needs.