Motor Oil 101 – Understanding a Motor Oil Bottle Label
If you’ve ever stood in the motor oil aisle, unsure where to start, you’re not alone. Engine oil offers so many combinations and selections that finding the one your vehicle needs can be intimidating and complicated. Choosing the right oil and oil filter for your vehicle is crucial to maintaining the life and performance of your engine. Keep reading as we break down everything you need to know to understand motor oil bottles.
What do the numbers mean?
When you look at a bottle of engine oil, you will notice a combination of letters and numbers, such as 5W-20 or 10W-40. These combinations represent the engine oil viscosity, which is important when choosing the correct oil for your vehicle. Viscosity measures how thick the oil is or how easily it flows through the engine at different temperatures. Oils have different viscosities and react differently to changing temperatures.
The first number, before the W, is the oil’s viscosity at colder temperatures. The W stands for winter. The lower the first number, the thinner the oil, and the better it performs in cold temperatures. Thinner motor oil can flow faster and more quickly through the engine when the vehicle is started. The higher the number, the thicker the oil, helping it to flow slower and creating more protection for the engine at high temperatures. The lower the number, the thinner the oil is, and the more easily it flows. The second number, after the W, is the oil’s viscosity at high temperatures when the engine is at its standard operating temperature or when your vehicle has been warmed up. A higher second number indicates that the oil stays thicker at high temperatures.
Getting the correct letters and numbers on your oil bottles is crucial to engine health. Engine oil is critical as it helps to lubricate engine parts, reducing friction and wear. This wear is further reduced with the use of a quality oil filter. You should consult your vehicle's owner's manual to find the specific oil needed and the best oil filter needed.
What is the Donut?
The API Donut symbol on oil bottles shows consumers that the oil meets specific API standards, ensuring that the oil will work well and provide the necessary protection. Typically found on the bottle's back label, the Donut is divided into three sections.
The top of the Donut shows the engine oil’s API Performance Level. Oils designed for cars, vans, and light trucks with gasoline engines will have an “S” for the Service category, while oils intended for vehicles with diesel engines will show a “C” for the Commercial category.
The center of the Donut refers to the oil’s Viscosity Grade.
The bottom of the Donut tells whether or not the oil has Resource Conserving properties. This section applies to oils for gasoline-engine cars, vans, and light trucks that meet standards to improve fuel economy and reduce emissions.
Who are API and ILSAC?
API (American Petroleum Institute)
The American Petroleum Institute is an organization that sets standards for motor oils and ensures that they meet specific performance and quality guidelines. An API-certified oil meets certain standards for protecting engine components, reducing emissions, and enhancing fuel economy. Consumers can identify quality motor oils for gasoline and diesel-powered engines by looking for an API symbol.
ILSAC (International Lubricant Specification Advisory Committee)
The International Lubricant Specification Advisory Committee is an organization that also sets automotive engine oil standards for gasoline vehicles. It was founded in 1992 as an initiative between the American Automobile Manufacturers Association and the Japan Automobile Manufacturers Association. The committee aims to help vehicles perform well and last longer by ensuring automotive oils meet specific requirements and standards. ILSAC oil ratings include more testing than API categories.
Understanding engine oil bottles and labels can make a big difference in ensuring your engine runs smoothly and efficiently. Now that you know what the different numbers, letters, and symbols mean, you can easily choose the engine oil that fits your vehicle's needs. The right oil and oil filter save you money and make your engine last longer.
Motor Oil 101 – Understanding a Motor Oil Bottle Label
Resources
