Nulon aditive in engine oils
I worked for a major transport company some years ago and were convinced that this product would be very beneficial in reducing engine wear and increasing fuel economy.
Tried it in naturally aspirated and turbocharged diesels with the result that it glazed up the bores and oil consumption went through the roof. Couldn't get rid of it fast enough! Agree with other posters, good oil will have all the additives required.
I am old enough to be around when the expensive "fad" additives such as Wynns and STP were the be all and end all.
They may have had some benefit in final drives but very risky in engines...just my 2 yuan.