After reading the entire thread, I would like to offer up something that has not been discussed . ( If it was ,I missed it , sorry) ..
After retiring from the fleet maintenance industry after 33 years, (journeyman mechanic for 20 years before that), the one thing that scares me about longer distance maintenance intervals is the REST of the vehicle ...Sure ...You can run 5K/7.5K/10K oil changes ... Who looks at the bottom of the vehicle between LOF services??? Brakes, steering parts, suspension, exhaust parts/tires call ALL go bad at any time .. Sure ..Most of us here have the smarts to know when something is going wrong, & tend to look into it ASAP.. What about Fred the everyday driver ?? What's that noise?? Hmmm.. I'll have them look at it during the next oil change .. ( 8K down the road?? ) .
Gee... The wheel could not have fallen off, I just had the oil changed *** miles ago ....
Most everyday drivers & people that drive company supplied cars tend to "stretch" maint intervals .. Manf says LOF at 5K ?? Ahhh.. I'm busy this week .. I'll take care of it later ...I've seen "later" turn into a 10K nightmare issue ...
My recommendation ?? Any quality "Name" oil that meets the manf requirements with quality "Name" oil filters, changed at OR BEFORE the manf suggested interval should allow ANY of today's vehicles run 150K to 200K miles with no issues ....
As hot as today's engines are designed to run, cam phasers & synchronisers controlled by oil pressure , ANY sludge or varnish is a recipe for disaster ....
Oh.... Don't even get me started on the "DEXOS" oil program from GM ..
Bob...