Somewhat new to the forum here... I've been a member, reading, just not many posts.
So I understand that the 6 liter likes to chew on it's oil, I would tend to agree with that, as I've ran 5w-40 syn from a couple vendors and even 15w-40 syn as well. Where I'm confused is the statement of 'shearing down to 30 weight'.
Is this making the statement that 'we' should start out with 5w-30 or 10w-30 or 15w-30 (I don't think that 15w-30 exists though) instead of 40?
My latest oil changes have been with royal purple oil, the 15w-40 worked well enough in the summer, but the motor lacked snap or crispness in the winter is was like driving a bus, I went back to the 5w-40, and it seems good, winter and summer.
Now... on to the shearing... at around the 5k mark, no matter what oil I'm running, I really seem to notice more ignition noise and more vibration from the engine. So, assuming the oil has been 'sheared' to 30w, wouldn't starting at 30w give the same noise and vibration levels at the beginning of the change as it would at the end since it's starting and presumably ending at the same 30w viscosity? By that logic, would it not theoretically be better to start at 50 and let it chew down? Something doesn't make sense.
I haven't ran any 10w-30 through it yet, and will likely do another 5w-40 RP run since I still have some remaining. It doesn't burn any appreciable amount of oil, but based on the noise and vibration levels, I'm really not that inclined to push to 7.5k or 10k based on what I FEEL, though I agree, the iron and other wear indicators show it to be just fine, and likely could go longer... so what the heck is it I can hear and feel, but can't seem to quantify analytically?
Here's my 15w-40 RP report
MI/HR on Oil 6990
MI/HR on Unit 76990
Date 12/27/2014
Make Up Oil Added 0
ALUMINUM 4
CHROMIUM 1
IRON 16
COPPER 2
LEAD 5
TIN 1
MOLYBDENUM 2
NICKEL 0
SILVER 0
TITANIUM 0
POTASSIUM 0
BORON 67
SILICON 3
SODIUM 4
CALCIUM 2428
MAGNESIUM 28
PHOSPHORUS 1088
ZINC 1233
BARIUM 0
SUS Viscosity @ 210°F 61.7
cSt Viscosity @ 100°C 10.7
Flashpoint in °F 405
Fuel % 1
Antifreeze % 0
Water % 0
Insolubles % 0.1
So I understand that the 6 liter likes to chew on it's oil, I would tend to agree with that, as I've ran 5w-40 syn from a couple vendors and even 15w-40 syn as well. Where I'm confused is the statement of 'shearing down to 30 weight'.
Is this making the statement that 'we' should start out with 5w-30 or 10w-30 or 15w-30 (I don't think that 15w-30 exists though) instead of 40?
My latest oil changes have been with royal purple oil, the 15w-40 worked well enough in the summer, but the motor lacked snap or crispness in the winter is was like driving a bus, I went back to the 5w-40, and it seems good, winter and summer.
Now... on to the shearing... at around the 5k mark, no matter what oil I'm running, I really seem to notice more ignition noise and more vibration from the engine. So, assuming the oil has been 'sheared' to 30w, wouldn't starting at 30w give the same noise and vibration levels at the beginning of the change as it would at the end since it's starting and presumably ending at the same 30w viscosity? By that logic, would it not theoretically be better to start at 50 and let it chew down? Something doesn't make sense.
I haven't ran any 10w-30 through it yet, and will likely do another 5w-40 RP run since I still have some remaining. It doesn't burn any appreciable amount of oil, but based on the noise and vibration levels, I'm really not that inclined to push to 7.5k or 10k based on what I FEEL, though I agree, the iron and other wear indicators show it to be just fine, and likely could go longer... so what the heck is it I can hear and feel, but can't seem to quantify analytically?
Here's my 15w-40 RP report
MI/HR on Oil 6990
MI/HR on Unit 76990
Date 12/27/2014
Make Up Oil Added 0
ALUMINUM 4
CHROMIUM 1
IRON 16
COPPER 2
LEAD 5
TIN 1
MOLYBDENUM 2
NICKEL 0
SILVER 0
TITANIUM 0
POTASSIUM 0
BORON 67
SILICON 3
SODIUM 4
CALCIUM 2428
MAGNESIUM 28
PHOSPHORUS 1088
ZINC 1233
BARIUM 0
SUS Viscosity @ 210°F 61.7
cSt Viscosity @ 100°C 10.7
Flashpoint in °F 405
Fuel % 1
Antifreeze % 0
Water % 0
Insolubles % 0.1