I was mentioned so let me chime in. I have used synthetic oil in my diesel pick up and had it lab tested .Their recommendations were that based on my usage i should change my oil at 6500 miles. At the time i was pulling a 32ft. trailer with my Jeep inside . Now I pull my Jeep behind me and based on two of my friends who have logged 275k miles and the other 450K miles on this V-10i consider that a good sign to use the Mobil 1 like they do. Neither truck had any engine issues, the 450K did drop a cylinder at the end of it's life. Costco offers Mobil 1 and I stock up when it offers the rebate. Previous gassers ,K-5 Chevy Blazers, both went over 250K without engine issues.One never had the valve covers off.
First and foremost a consistent maintenance program using quality products is absolutely the best extended warranty you could ever purchase. Research available online conducted by independent research has shown comparisons that I trust. I buy good filters, tires and oil and encourage others to do the same or the best you can afford.
Your results AND opinions may vary.......
