I used Mpbil 1 from the time it came out until I retired a few years ago. I used it in many different vehicles successfully, always remembering that it was advertised initially as a 25,000 mile or once a year oil change oil. So that is what I always did for more than 20 years, with no problems and no noticeable engine wear. I usually put 18,000 to 20,000 miles a year on my vehicles; on my 1986 Thunderbird I put 140,000 miles in 7 years, changing the M1 every January. It was still as quiet as new when I traded it.
I notice that most of the above M1 users are changing using OCI's more appropriate for dino oils. At the intervals being mentioned, dino will make any engine last over 200,000 miles. I am now retired, driving about 6000 miles a year, and changing oil twice a year using dino. It would be a waste to use M1 for this low mileage. What I wonder is why they say this new M1 is only good for 15,000 miles?
