You worked for Shell oil, did you ever work for a dealership, a NY dealership? Cars sit in lots for a very long time waiting when there is a problem and the suggested maint interval was not followed. EG 0W30 in a 5W20 application, oil that was supposed to be changed every 6 months or 7,500 miles being in the sump for 1 year or 12,000 miles. Ask any service writer what happens in these cases if the engine fails because of the wrong oil. I say follow the mfg suggestions, follow the intervals they suggestm not what Amsoil suggests, then you reduce the risks.
Amsoil is in business to sell their products, the are not the company that made the vehicle, nor did they set the specs or write the OM. Why can't you understand that? I don't believe the Amsoil BS, sorry.
How about those bad filters?
Why do I like Red Line? Because IMO it is a better oil, and I feel more comfortable dealing with them than Amsoil. Pretty simple. You can copy and paste until you're blue in the face, I WON'T USE AMSOIL ANYMORE! Nada, no way, no cigar!