Oil is oil, right? But when you go to buy the stuff, there’s a huge range of options available at all kinds of prices. When you pick up a bottle or look more closely at the specifications you’ll be met with a seemingly random series of letters and numbers and, what's worse, they're similar to those on another identically priced bottle, but different enough to make you wonder if there's something else you should know! Fear not, we’re here to talk you through what it all means, in a (mostly) jargon-free manner. We've let the boffins get in on this though as they're the only ones that truly understand it all...
There are three core types of engine oil on the market: mineral, semi-synthetic and synthetic.
- Mineral oil is the cheapest and is essentially a constituent of crude oil, produced after it is refined. Few car companies recommend this these days as it generally doesn't come with the engine-cleaning detergents that are required these days and has a limited temperature operation range. Saying all that, it's perfectly fine for older engines whose tolerances are less extreme and that are used in a mild climate without freezing or really hot weather.
- Synthetic oil is the most expensive, but for a reason. It has been engineered by scientists to work over a wide range of temperatures and conditions, while reducing drag on the engine to help reduce fuel consumption. It also actively cleans the engine's internals as it’s pumped around.
- Semi-synthetic oil is a blend of mineral and synthetic oil to help bring the price down.