You shouldn't have to flush again, especially using Mobil-1 as its detergent properties are excellent. Be sure to keep a handful of PCV valves (about $4 each) on hand and change it every other oil change, as that will typically keep excessive oil consumption under control.
I know many are proponents of extended oil changes and the synthetics are certainly good for it, but remember that oil keeps dirt and contaminants in suspension to be removed at the filter. What the filter doesn't get stays in suspension and the filter has a limited capacity. So the further you push that the more likely your filter will be running in bypass mode and not filtering anymore, meaning the oil is just circulating crap and crud throughout your engine and it's tight-tolerance bearing surfaces. There aren't little magic elves cleaning things in there, it's all up to you. Pushing it further means higher concentrations of contaminants having their way in your motor. So if you do the math on the cost difference between 3000 mile changes and 5000 or higher you'll see it's a minor expense for such a huge gamble. On an average 15,000 mile year you're looking at an average cost difference of $74 (5 quarts Mobil-1 $25, Mobil-1 filter $10, 1 PCV valve $4) per year. Isn't your VX worth $70?
Reply With Quote