AAA funded it's own tests to determine if Top Tier gasoline's really do keep our engines cleaner than the government mandated LAC = Least Additive Concentration gasoline's. It's a rather long report, so open, read & view when you have time to absorb all of it. Enjoy, I sure did.
http://www.aaa.com/AAA/common/AAR/fi...ull-Report.pdf


EDIT: 4-19-21 Gasoline White Paper. Don’t Be Fueled: Premium Not Always Worth the Price | AAA Newsroom

 

Good read!