Thank you. Thats the type of information I was seeking.
The quote I received from a Cassie at Granger was $2,510 for the 10yr - 100k mile Premium Maintenance Plan with 5k intervals. If I opted for the full-synthetic oil option it would be an additional $500.
Yes to the Premium plan with full synth change out. My oil tests show on my 3.5L show accelerated sheer oil viscosity, sheering out or 30 to 20 in as little as 2300 miles for a mid cycle oil lab test. With that, go with full synth as a prudent and reasonable choice.
What kind of driving are you doing when citing that test. Are you towing heavy loads?
Just the normal city/highway driving. No towing and I am showing the motor sheered both Pennz Ultra P and Valvoline R&P in about 2500 miles out of 30 and down to 20 weight. Sheering the viscosity package down at the halfway point of a 4K cycle is something to note and keep an eye on. The real key is what is the metal wear per 1000 miles to keep an eye on.
Yes, 30 weight is sheering down to 20 weight. Some of this might not be as concerning as one would think as long as metal wear indicators stay low enough. The history of the 3.5L going back in 2011 was that it was originally specified with 5W-20, where sometime thereafter they bumped that up to 5W-30. The real indicator of concern is the metal wear indicator number per 1000 miles. If that is ok, going to 4K miles is ok as long as the viscosity doesn't dip down below 20. I will have more information on that performance profile for Valvoline R&P when I test and drop the oil at 4k miles. In any case, full synthetic change out at 4k or 5K interval max seems like a good idea with a Premium Plan to me.
I wonder if that has to do with the higher shear loads imposed by the turbocharger on that V6 engine? obviously cylinder pressures would be much higher and piston side loads and piston ring loads also higher.
Yes to what you cited. Forced induction motors are hard on oils. I am actually a pretty mild driver so it’s not like I am stomping on and building up boost very much, eg, on ramp speed up and certain passing situations but from looking at my boost pressures on the turbo, I am actually a very mild driver
After rereading a few of the blackstone threads, it does appear that the 3.5's fuel dilution causes the viscosity to decrease in shorter interval samples. My previous statement was incorrect.
So am I understanding correctly that with that information, utilizing full synthetic oil should be recommended? Full synthetic will help mitigate that viscosity issue?
I'm not a tribologist nor have I done any used oil analysis myself, so can't answer that specific question, but I have been using only full synthetic for a couple decades.
