Quote:
Originally Posted by oilteq
The W stands for winter, not weight, and the test temperature varies with the grade you are qualifying for.
|
Not according to my understanding. The "W" is commonly considered to mean "Winter", but it just specifies that it's a multi-viscosity oil.
Quote:
Originally Posted by oilteq
When base oil breaks down, whether synthetic or petroleum oil, it gets thicker, not thinner.
|
Again not my understanding. They start with the lower viscosity oil, and add additives to make it equivalent to the thicker viscosity when hot. As the oil breaks down, the oil viscosity tends to fall somewhere in between the two ratings - it acts like a thinner oil...
But I could be wrong...