Walk into any AutoZone, or any auto parts retailer, and you will see shelf after shelf stocked full of different types of engine oil. Most auto parts retailers carry about a dozen or so brands of oil. And each brand has several different oil "weights". Seeing this huge display can make the process of purchasing a quart of oil somewhat intimidating for someone who just needs to purchase some oil and doesn't know anything about oil types and which one they should use in their vehicle.
Each brand of oil has different types of oil and various weights of oil. The different types of engine oil are conventional oil, synthetic oil, synthetic blend oil and high mileage oil. Now, let's break down these four oil types and see their differences.
Traditional mineral, or conventional oil, is made by the process of refining crude oil that is drilled for and pumped from out of the ground. Conventional engine oil is made with additives that help make sure it has the right heat tolerance, as well as the proper breakdown resistance and viscosity that car engines require. Conventional oil offers sufficient lubrication and works well for most vehicles.
Synthetic oil is made from a base oil that is man made. It is made up of chemical compounds that are made artificially by breaking down petroleum molecules and rebuilding them. Synthetic oil is specifically designed to give you the highest level of lubrication for both high and low temperatures. Synthetic oil also has properties that help to clean your engine and gives better protection against heat build-up, increasing engine longevity.
Synthetic blend oil, also called semi-synthetic or part synthetic, is made by combining conventional and synthetic base oils. Synthetic blend oil is widely used by drivers who put more of a load on their engine than people who drive under normal conditions - for example, someone who pulls a trailer or someone that does a little bit of off-roading. They give your engine better protection under heavier loads and higher temperatures because they don't evaporate as easily as conventional oils. Synthetic blends are designed to give some of the same benefits of full synthetic oil at a reduced cost.
High mileage engine oil is targeted more towards engines that have been driven 75,000 miles or more. As you put more miles on an engine, the inner parts can start wearing out. Seals and gaskets are a prime example of this as they can become very brittle and shrink as they age, causing oil to seep past them and leak out of the engine. High mileage oil contains seal conditioners that can rejuvenate seals and even expand them slightly, helping to reduce oil loss. Other benefits of using high mileage oil is that it has more detergents added to it, which helps clean out engine sludge, as well as more additives for reducing wear on your engine.
Now that we have broken down the different oil types and their benefits, you can better determine which type of oil to use in your vehicles. Conventional oil costs less and break down faster. Synthetic and synthetic blend oils provide high levels of lubrication for high and low temperatures and they help clean the engine and protect against heat build up. They also cost a bit more than conventional oil.
Before making any purchase, it is recommended that you follow the recommendation from your vehicle owner's manual to make sure you use the right oil in your vehicle.If you don't have the owner's manual, you can pop the hood and check the oil fill cap to see if it is marked on there. Otherwise, you can find out fairly easy by doing an online search.