Viscosity Grades and Seasons: How to Choose Right Engine Oil?

Not all of us know what engine oil in our engines is for. And even fewer actually know that the choice of engine oil depends on the season or climate the car is used in. The thing is that engine oil goes in different viscosity grades that define how thick oil is and its fluidity. So how do you know you use the right oil type and how to choose the best motor oil for the weather conditions you are in? So, engine-oil.ie, the leading online retailer of motor oils and automotive accessories, recommends consulting the owner’s manual that went with the car.

What is the role of engine oil in your car’s work?

Engine oil is a substance that lubricates engine parts and thus prevents them from rubbing against each other, overheating and wearing down too fast. It also protects metal engine parts from corrosion and helps to clean out dirt and carbon deposits. Naturally, the quality of this job directly depends on the quality of motor oil, and the latter directly depends on its composition. You must have heard that there are different types of oil: mineral (conventional oil made out of petroleum), semi-synthetic and fully synthetic. Unlike with food, synthetic oil works best when it comes to the engine. Fully synthetic oil is more expensive, but even if you decide to buy the best possible high-performance oil, you need to know a thing or two about viscosity grades and seasonal oil usage. Because the wrong choice can reduce the expected performance benefit and even lead to undesirable (and expensive) consequences such as engine failure…

Viscosity grades and seasons: how to choose?

First of all, what is a viscosity grade?  It is a number on the generally accepted scale developed by the Society of Automotive Engineers. For single-grade oils, the rule is like this: the bigger the number, the thicker (and, therefore, less able to flow) the oil. For example, SAE50 is thicker than, say, SAE30. With single-grade oil, the measurement is made when the engine is working. Multi-grade oils have 2 digits separated by the letter W (Winter): like 5W-20 or 10W-40. The first digit tells the viscosity grade at start, and the second one – at the engine’s working temperature. The multi-grade oil assortment enables you to select oil that will adjust to the weather conditions better and provide desirable performance.

So, why are these numbers so important when it comes to seasons? It’s because the higher the temperature outside, the thicker you need oil to be at the engine’s operating temperature (for example, 10W-60). For winter months, thinner oil will work better. While shopping, you will notice that some oils have 0 as their first digit. They are very thin oils that provide immediate lubrication when you start your engine at below-freezing temperatures. If you are looking for a compromise (which is quite reasonable if you usually drive in moderate climate without dramatic drops of temperature), 5W-30 oil will work well. We hope this general overview is useful. But don’t forget that your vehicle’s manufacturer has already defined the type of oil your engine needs, so you’d better consult your manual first.