Have you ever found yourself staring at a bottle of engine oil, wondering what those numbers and letters on the label signify? Well, you're not alone. Today, we're hopefully going to decode those labels for you.
Understanding Single-Grade vs. Multi-Grade Oil
Firstly, let's differentiate between the two primary types of oil:
As the name suggests, Single-Grade Oil has one set of digits following the "SAE" (Society of Automotive Engineers) designation. For instance, SAE 30.
Multi-Grade Oil displays two sets of digits behind the SAE, like SAE 15W-40.
Contrary to popular belief, the "W" (e.g., 15W) in the first number seen on a Multi-Grade Oil container label doesn't stand for weight. It represents "winter." This number indicates the oil's viscosity at 0°C (32°F). The lower the number, the thinner the oil at cold temperatures. This ensures better flow and protection during cold snaps.
The second number on a Multi-Grade Oil container label (e.g., 40) signifies the oil's viscosity at 100°C (212°F), which is approximately the operating temperature of most engines. A higher number means the oil will be thicker at these temperatures, providing a protective layer between engine parts.
SAE stands for the Society of Automotive Engineers, the group responsible for setting these oil standards.
Single-grade oil, like SAE 30, doesn't have the "W" designation. This means it maintains a consistent viscosity, acting as an SAE 30 oil, regardless of the temperature. While it offers stable performance, it might not be ideal for colder climates due to its inability to adjust viscosity based on temperature.
Choosing the Right Oil for Your Needs
When selecting an engine oil, it's important to consider the climate and application.
For example, if you reside in a colder region, opt for a multi-grade oil with a lower "W" number. For hotter climates, a single-grade oil might suffice. And for heavy-duty applications where the engine runs at high temperatures for extended periods, a higher second number (like 50 or 60) might be more suitable, offering better protection.
Understanding engine oil numbers can help you make an informed decision, ensuring your engine remains well-lubricated and performs optimally under various conditions. Remember, the right oil can make a world of difference!
If you have questions about any of the steps outlined above or are just more of a visual learner, head over to our YouTube channel and watch our step-by-step video (also attached below)! Leave a comment or question and receive a personal reply from Brent, our resident John Deere expert. Be sure to subscribe!