Originally Posted By: ChiTDI
If you do decide to make the switch, and that's your call, I would indeed shorten the first OCI to 4 or 5k.
Seems the "cleanup" is unpredictable in severity.
Well....I cannot recommend that you SHORTEN OCI to 4000 miles as I have never gone as long as 4000 miles in my 49 years of driving and changing oil. I do think that it would be a really good idea to change your filter at 1500 miles, then change oil and filter at 3000 as "cleanup is indeed unpredictable in severity."
I recommend high mileage oils not for the maybe more seal conditioners and the extra detergents/dispersant's. High mileage synthetic oils such as Mobil 1 and Valvoline MaxLife, also have more anti wear, more FM, more antioxidants, a much higher HTHS, higher 100C cSt, and on. Valvoline 10W-30 synthetic MaxLife even meets the tougher European ACEA A3.
Top quality HM oils, such as Mobil 1 and Valvoline are a breed unto themselves. They are MUCH, MUCH, more than seal conditioners and detergents.