Engine oils are available in a wide selection of varieties to meet the needs of all types of vehicles, driving habits, and mileage.
First, it is essential to consider two key elements relevant to all oil types: viscosity and weight.
- Viscosity is a measure of the fluidity of oil. The oil’s viscosity increases with its thickness, which causes it to flow more slowly at low temperatures. Conversely, low viscosity indicates that the oil is thin and flows more quickly. The viscosity rating is given to all motor oils by the Society for Automotive Engineers (SAE). You will generally see the viscosity level of the oil indicated on the container.
- The weight is another measure of the oil’s viscosity and is also given by the SAE. This number is allocated to the oil based on how well it flows at 210°F, which is roughly the operating temperature of most engines.
A brief description of the various types of oil is provided in the following sections.
Conventional oil is sometimes referred to as “standard” or “regular”. This oil comes from crude mineral oil and is only partially refined, making it cheaper than other oil types. Conventional oil can provide sufficient protection for most engines, but it gets dirty more quickly. This is why this oil requires more frequent oil change services. However, when changed routinely, this oil can help your engine reach 150,000 miles or more.
As the name implies, full-synthetic oil is entirely manufactured in a factory or lab and is highly refined. Compared to conventional oil, this oil breaks down more slowly and can better withstand high temperatures. It is more expensive than other oil types but provides engines with the highest performance and protection. For modern vehicles, most manufacturers recommend using full-synthetic oil.
Synthetic blend oil combines the best aspects of conventional and full-synthetic oils. The lower price of synthetic blend oil is beneficial for drivers who cannot afford full-synthetic oil.
About 45% of all vehicles use either a synthetic blend or a full synthetic oil. When deciding which option is best suited for your vehicle, two factors should be taken into account.
- Due to its better chemical stability, performance at high and low temperatures, and overall viscosity, full-synthetic oil helps further extend your engine’s lifespan more than synthetic blend. Additionally, full-synthetic oil resists thermal breakdown, oxidation, and oil sludge buildup more effectively.
- Synthetic blend oil contains some mineral oil, and its performance depends on how much mineral oil is present in it. The higher the amount, the lower the performance and the shorter the oil’s longevity. However, compared to full-synthetic oil, synthetic blend oil is cheaper and only needs to be changed slightly more frequently.
An older engine that has run over 75,000 miles needs extra protection. High-mileage oil was designed to tackle this problem. These oil attack problems, such as faster oil burn-off, engine corrosion, and leaking gaskets, can spread like plagues in older cars. High-mileage oil offers superior protection with viscosity modifiers, specialized cleaners, anti-corrosion agents, and seal conditioners.
Diesel engines, which are larger than gasoline engines, absorb more dirt and grime. So they need an oil that can adequately keep them clean and protected. Diesel motor oil has powerful additives that help in achieving this. A diesel engine requires more frequent oil changes due to the large quantity of dirt and debris that it collects.
When it comes to determining which oil should be used in an engine, there is no one-size-fits-all answer. The best choice is to use what your vehicle’s manufacturer recommends. The manufacturer often recommends a range of oils to choose from to account for different environments and driving habits. Additionally, it is OK to switch between synthetic and conventional oils—doing so does not damage your engine.