I posted this a while back but I think the thread got lost. Hmmm, I do believe Mobil's claim about those mileage intervals regardless of operation, but geez, not sure if I want to go 15,000 miles on an oil change!
Sorry Eric for repeating the information. What prompted me was an add yesterday during Formula 1 race (what a race! It is going to be very interesting season.).
I believe that oil can last 15,000 miles. As we discussed it before the filter might be a problem. It seems to me that most of us have been condition rather well by the 3,000 miles intervals in the past. It is history. New oils especially synthetics are much better and can last so much longer. Not to mention that they offer superior protection particularly in low temperatures (cold start ups).