Castrol GTX 20-50

I'd like to tell you a story and then let you decide whether it applies to this discussion or not. When I was a kid (I'm a really old guy) there was a well-known automotive journalist named Tom McCahill who for years had a monthly column in Mechanix Illustrated magazine. He was one of the first journalists to do road tests, and was known for his Assiduous and Always Around-the-Clock Alliterative writing style.

In 1949 General Motors released new V8s for the Oldsmobile and Cadillac. They had the first hydraulic lifters, and required detergent oil. The instruction manuals for the cars said that the engine warranty would be void if you used non-detergent oil. McCahill wrote in his column that detergent oil was just a sales gimmick, and that his readers should feel free to continue to use non-detergent oil if they desired. Based on his recommendation as an "authority", many of his readers did use non-detergent; their lifters seized or quit working; and GM refused to cover the repair under warranty. At that point, McCahill backpedaled from his previous statements in a manner that would have made Muhammad Ali proud!