Posted on 2/14/2014
Many people often have questions for their mechanics about the best type of oil they should use in their vehicle. One of the most often misunderstood parts of choosing the right type of oil is the number system that is used for rating oils. The weight of oil, also known as viscosity, refers to the thickness or thinness of the oil. The Society of Automotive Engineers, SAE, establishes temperature requirements for oil. Those temperature requirements range from 0 degrees Fahrenheit (low) to 210 degrees Fahrenheit (high). Oils that meet the low temperature requirements established by the SAE will have a “W” after the viscosity rating. A common example of this would be 10W. Oils that meet higher SAE ratings will not have a letter. For instance, SAE 30. Special tests are conducted to determine the viscosity of different types of oil. First, it is heated to a specific temperature and then the oil is allowed to flow out of a certain size hole. The viscosity rating of the oil is d ... read more