quite frankly, I don't expect it to perform much better than the blend.
Al, if you didn't do a purge prior to change over, you may find that the first change would not be the best to go on to extend drains. Change over from one type of oil to another does several things.
You always have the possibilty of additive clash which an additive from the previous oil can compromise the performance with the newer oil. Second, a lot of oils leave some acids and such and the new oil will have to clean or neutralize those acids right off the bat therefore putting more strain on the new oil right from the git go.
This is why it is a good idea to take something like the auto rx or neutra 131 and run before change over. The neutra 131 will neutralize these left over acids and clean any residue prior to change over,then your new oil can get a better starting point.
When this is not done, then you should run the oil only to a standard drain interval(5k in this case), then do a change out. Then look at extending from that point because by this time, you have pretty much neutralized all the acids and such.
The oil analysis from a first drain is very seldom a good picture on how well an oil will hold up unless the steps to flush or purge the system prior is taken because of the probable left over contaminents and such which effect the oils ability to hold tbn. This is why Schaeffers never recommends extending drains right off the bat, but steps it up after the first one has been run and a trend is set.
Of course each car and oil is going to be different on how it looks. You can take a real low quality oil run for 7k, change over to a super high end oil(like schaeffers
) and it would overload the additive therefore shorting the life expectancy of the good oil. Then again, take a high quality oil, change over, and may never see any conflicts and degregation. This is why trending is important at reasonable drain intervals.
So in conclusion, this is the recommended method for a change over and how to consider extending your drain intervals. This is not just for schaeffers but for all oils.