I have over years have had the opportunity to attend oil company seminars with both Mobil and Penzoil. Both of those companies would tell you that oil doesn't last that long. I would even say Royal Purple doesn't last that long. This not because one is better than another or anything like that, but oil is designed to carry contaminants,because manufacturers are demanding this so it reduces exhaust emissions. So knowing that is demanded of the oil,it can only suspend so much before it rendered inadequate to cope with the task of lubrication and carbon deposits start forming as breakdown occurs. 5-7 km is deemed to be maximum life. Car manufacturers don't really car about the long term damage done to your engine, they want to show a cheap service schedule but after warranty your on your own, also most of us are demanding much more with spirited driving and power up grades.All the more reason to change your oil at least every 7500 km. Cheers Paul