So we can close the forum. In fact every forum.
Not everybody is born without memory and have to 'google' everything some people like a friendly chat.
Besides, I use Duckduckgo. Is that allowed?
Google is my enemy, they collect to many privat information.
The w stands for winter. It characterizes the properties of the old when cold and not under sheer.
The first number is the viscosity of the base oil in the bottle. In the case of 10W30 the oil in the bottle is a 10 weight oil.
The last number is the viscosity under sheer and higher temperature conditions. In the given example the 10 weight oil takes on the viscosity of 30 weight oil under sheer conditions due to “viscosity improver” additives.
The "W" in motor oil stands for "Winter". It indicates that the oil's viscosity has been tested at colder temperatures and is suitable for use in cold weather [1].
Motor oil is classified by its viscosity, which is its resistance to flow. The "W" rating (e.g., in 5W-30 or 10W-40) is part of a Society of Automotive Engineers (SAE) grading system:
The number before the W (e.g., 5W) indicates the oil's flow characteristics at a cold temperature. A lower number means the oil is thinner at cold temperatures, allowing for easier engine starting and faster oil circulation in winter [1].
The number after the W (e.g., 30) indicates the oil's viscosity at normal operating temperatures (around 100°C or 212°F) [1].
Therefore, a 5W-30 oil acts like a 5-weight oil when cold (for winter conditions) and a 30-weight oil when hot [1].
Forest I was about to tell the individual that asked the question to do exactly what you said I didn't know either. My response is from Google's AI engine.
