You just received two very accurate responses from these guys. The very best flush that can be done to any engine is frequent, (9,000 miles is anything EXCEPT frequent) hot, overnight oil drains with a fresh filter every time.
Making up for a lack of frequent oil change by flushing is IMHO a "BAD, BAD, BAD" plan. Flushing is a step you take with a neglected engine. It cannot reverse any wear that was incurred by excessively long oil change intervals.
I don't care what kind of oil goes into an engine. I don't care if it contains KRYPTONITE, it MUST be changed often if you are seeking long engine life. The reason you change the oil is that it is the only means you have of cleaning the inside of the engine. Additionally, regardless of the oil used, there is particulate matter, not trapped by the oil filter that builds up in the oil. This particulate matter accelerates wear, particular on timing chains.
Using Mobil One is great, but you still must change it hot and change it often. Also, you did not say what car you are talking about. If this is a diesel, you should use a Universal Grade oil. If you want to use Mobil One, use Mobil Delvac One which is a Universal Grade. These oils are blended with additional additives for soot dispersal, very important in a diesel, but unnecessary in a gas engine.
In fact if it is a diesel, you would be better served using a Universal Grade oil than regular Mobil One. Mobil Delvac One, however, is the ultimate Universal Grade.
Best of luck,
Change oil hot and change oil often,