What does the W mean in 10W-40 motor oil?

Answer The "W" in 10W-40 stands for "winter." One of the purposes of motor oil is to protect against wear. When motor oil was originally developed, winter weather was a major source of engine wear.Source:... Read More »

Top Q&A For: What does the W mean in 10W-40 motor oil

What Does the "5W-40" in Motor Oil Mean?

Motor oil provides lubrication to a vehicle's engine, keeping the moving parts from overheating due to friction. It also transfers heat from the combustion cycle, helps keep the engine clean by sus... Read More »

What does SL SJ mean on motor oil?

According to the American Petroleum Institute (API), SL motor oil grade is used in gasoline engines in automotive vehicles made in 2004 or earlier. SJ motor oil is used in gasoline engines made in ... Read More »

What does the"w"mean in 10w40 motor oil?

The "W" signifies the word winter. The purpose of this is to show the resistance level of the oil to flow in winter temperature conditions, with the number before the "W" relating to the specific v... Read More »

What does the single letter on motor oil mean?

Motor oil includes a two-letter classification, not a one-letter classification. The two letters represent the American Petroleum Institute service rating. The first letter is either an S, indicati... Read More »