You might be aware that motor oils are labeled with designations like 5W-30 and 10W-40. If you've been wondering what this means, you're not alone. Many of the customers at Bob-Boyd Lincoln, Inc. are unaware of what these numbers are letters are for, so here's a quick guide.
These designations indicate the viscosity of motor oil. Viscosity describes how thick or thin a liquid is. Thin oils can move around easily and can do a good job of helping engines start quickly when it's cold. Thick oils are strong and durable, and they are ideal for use in high temperatures. Ideally, you'd want a motor oil that does well in your specific climate.
If a motor oil has a designation of 10W-40, this means its viscosity in the winter (W) is 10. Specifically, this is its viscosity when it's zero degrees Fahrenheit. Its viscosity when the temperature is 100 degrees is 40.