Oil and filter changes are part of your routine maintenance schedule. It’s a service that’s among the easiest to do, even for a budding DIYer. And while it’s a simple procedure, few things are as crucial as using the right oil in the engine. Options abound including different viscosities and a range of oil types, and making the wrong choice could result in sudden and expensive repairs.
Engine oil prices range from around 4 EUR per liter to 20 EUR or more per liter, and your engine could take anywhere from four to eight quarts in most cases. But more important than the cost of changing the oil in your car is ensuring you have the right oil to protect the engine. Here’s what you need to know about choosing the right motor oil.
Knowing what roles motor oil plays in your engine’s health can help to understand why choosing the right oil is so important. Oil is first and foremost recognized as a lubricant, keeping parts separated by a thin film of molecules that act like tiny ball bearings, preventing them from rubbing against each other. Not only is it a lubricant, but engine oil also:
The Society of Automotive Engineers, or SAE, has developed a grading system for engine oil. One common grade is 5W-30 engine oil, and it can be generally explained for how it performs based on its grading.
The first part of the number, 5W, indicates how well it pours in cold weather since the W stands for Winter. The lower the number, the better it flows in the cold. The second part of the number – in this case, the number 30 – indicates the oil weight at normal operating temperature. The higher this number, the thicker it is when it’s warm.
The grade you’re looking for will be marked on your engine oil cap, in most cases. You’ll also find it in your vehicle’s routine maintenance guide booklet or online. If your manual gives two different possible grades, the one with the lower numbers is intended for winter driving. For example, a car might use 5W-20 engine oil in the summer but have 0W-20 oil recommended for winter.
Grade is only one portion of the motor oil equation. Perhaps even more important is the type of oil you use in the engine. And if you’re wondering, “Are all engine oils the same?”, no they are not. It’s true that they may all start with a base oil that’s refined from crude oil drawn from the ground, but there are some very distinct differences between oil types, even though you can’t see them with the naked eye.
Crude oil extracted from the earth in a variety of ways needs to be refined before it can be used in an engine. Once impurities have been removed, it’s mixed with detergents and additives that are intended to keep your engine clean and protected.
Once conventional oil has been put into the engine and used, it begins to degrade. Within a matter of months or a few thousand miles, it will be saturated by contaminants and particles that would otherwise damage the engine, and it begins to lose its protective qualities. That’s why oil changes are so important – it removes these harmful compounds from the engine for disposal.
Contrary to popular belief, synthetic oil is not completely synthesized. It’s formulated from crude oil, just like conventional oil is. However, the refining process is more thorough. Synthetic oil’s molecules are a more consistent size, allowing for better protection against wear inside the engine. It’s a higher quality base oil to start with, and that means it’s more chemically stable, resists oxidization better, and won’t lose its protective properties as soon.
Combined with a better base oil, synthetic engine oil also tends to have premium additives and detergents mixed in it. Because of that, synthetic oil keeps the engine cleaner, experiences less wear, works to protect at higher temperatures better than conventional oil, and doesn’t degrade as quickly.
The problem with full synthetic engine oil is that it’s expensive. A less costly option is a synthetic blend or semi-synthetic engine oil that offers similar benefits without such an expense. It starts with a mixture of synthetic and conventional base oils and receives additives and detergents, typically better than you’d find in conventional oil. It’s a popular choice for carmakers and service shops alike. And in most cars, it’s become the minimum required grade.
The minimum type of engine oil your car requires is specified in the maintenance guide, which you should always follow.
For naturally aspirated cars, it’s often conventional engine oil that’s the minimum standard. However, if you’d like extra protection for your engine, you can upgrade to semi-synthetic or full synthetic engine oil.
If your car has a turbocharger or supercharger, or if you have a high-performance model, the required type of oil is often semi-synthetic or fully synthetic. You should not downgrade to conventional oil as it doesn’t have the properties necessary to protect your engine as it needs.
Changing oil is routine, but the interval should never be neglected or extended beyond what your maintenance guide says. You can expect longer intervals from synthetic oil, typically, since it doesn’t degrade as easily, and 7,500 miles or more is common. For conventional oil, usually, an oil change should be performed every 3,000 to 5,000 miles.
If it’s time for an engine oil and filter change on your car, buy your motor oil at BuyAllParts.com.