Thank you for your reply Lineman.
I hear you. But, I have read TONS of comments from prior mechanics of all makes and models, 35-40 yrs experience, and none of them ever recommend going over 5K, that is, unless you're going to trade her in at 70K+ or earlier, esp any direct inject engines. They all swear by an oils Noack rating. The Noack volatility of an oil is defined as
the weight loss of the oil when it is held under isothermal conditions at 250 ˚C for a period of 1 hour under a constant flow of air. The lower the better 6.6-8.8, Pennzoil Ultra - Qkr State Ultimate Durability, respectively/ Mobil oil and a lot of dealer oils are in the 10.1-14.3 NOACK range, which is horrible. Then, take that over 5K+, like shooting cholesterol/lipids directly in your arms. The best value and availability is Qkr St, but here's the ratings. If you have a personal friend that's been a mechanic for 25+ yrs, see what they will tell you "off-line"...good luck sir.
Ultra 6.6%
Mobil One 10.1%
PLatinum 9.3
SynPower 11.6
Super Tech 11.1
Royal Purple 10.9
Quaker State Ultimate 8.8
Lucas Synthetic 14.9 (almost out of spec at 15%)
Kendall GT W/Titanium 10.9
Formula Shell 9.7
Castrol Edge 11.1
Amsoil OE 10.9
MotorCraft Blend 14.3