Proofreading is a lost art. I used to tell our finance director to please proof his emails because no one can understand them and you look like a dummy. Then I realized he was a dummy and a few other things too.
It’s supposed to improve lubricity, and function as an all-around “top oil.”
Our 41 Studebaker got top oil at every oil change. That was every 1200 miles. Then Kendall oil started billing itself as “The 2000 mile oil”.