Well, the owners manual lists differnt times for 'severe' conditons and not - 5,000 miles or 10K for oil changes (THIS IS UNHEARD OF!) I don't care how good oil is - oil filters haven't chaged all that much over the last 10 years or so - and they still can only clean so much for so long. Also, I do know that engines are made better to starttout, form the past, but still - beak in is critical for best performance in the long run. How about some miliage EXPERT opinions? I say 3K miles, and then switch to syntec, or #K miles on dino, another 3K miles on dino, and then go to ~6-7K between with synth. oils