Let's say (hypothetically speaking since still considering another full synthetic option) that I'm gonna give Amsoil a try, with analysis. Which of these 2 options would be the better bet, and why in relatively simple terms please. I note several differences, some I understand and some not a clue but the main things that stand out or the weight difference (5 vs 15w40) and TBN listed is much higher in the AME. Isn't this important for extended change intervals? And also, is this what may harm the enviro-crap on my 6.0 (EGR system)?
Pasting below the 'stats' of the 2 that I would consider using from their site. Yeah, I know the PCO is API listed, but I want the full synthetic if gonna try to go longer than 5k. Also, not to worried about the price difference of these 2 as it's only $8 or so for 4 gallons shipped. Lastly, I'm in TN, so there are a couple months per year it's down in the 20's or lower, but my X is garaged so it rarely starts cold below 40 or so... 15w40 is probably OK in other words....Can't wait for the feedback, this is why I come to work on Mondays.
<TABLE borderColor=#cccccc cellSpacing=0 cellPadding=4 width="100%" border=1><TBODY><TR bgColor=#cccccc><TD colSpan=2>
AMSOIL Synthetic SAE 15W-40 Heavy-Duty Diesel and Marine Motor Oil (AME)
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Kinematic Viscosity @ 100°C, cSt (ASTM D-445)
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14.4
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Kinematic Viscosity @ 40°C, cSt (ASTM D-445)
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89.7
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Viscosity Index (ASTM D-2270)
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167
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CCS Viscosity @ -20°C, cP (ASTM D-5293)
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4477
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Pour Point °C (°F) (ASTM D-97)
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-42 (-44)
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Flash Point °C (°F) (ASTM D-92)
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234 (453)
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Four Ball Wear Test (ASTM D-4172B: 40 kg, 75°C, 1200 rpm, 1 hour), Scar, mm
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0.35
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Noack Volatility, % weight loss (g/100g) (ASTM D-5800)
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6.8
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High Temperature/High Shear Viscosity
(ASTM D-4683 @ 150°C, 1.0 X 10<SUP>6</SUP> s.<SUP>-1</SUP>, cP
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4.4
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Total Base Number
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12.1
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<TABLE borderColor=#cccccc cellSpacing=0 cellPadding=4 border=1><TBODY><TR bgColor=#cccccc><TD width=600 colSpan=2>
AMSOIL Synthetic 5W-40 Premium Diesel Oil (DEO)
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Kinematic Viscosity @ 100°C, cSt (ASTM D-445)
</TD><TD align=middle width=80>
15.3
</TD></TR><TR><TD>
Kinematic Viscosity @ 40°C, cSt (ASTM D-445)
</TD><TD align=middle width=80>
92.6
</TD></TR><TR><TD>
Viscosity Index (ASTM D-2270)
</TD><TD align=middle width=80>
176
</TD></TR></CENTER><TR><CENTER><TD>
CCS Viscosity @ -30°C, cP (ASTM D-5293)
</TD></CENTER><TD align=middle width=80>
5852
</TD></TR><TR><TD>
Flash Point °C (°F) (ASTM D-92)
</TD><TD align=middle>
226 (439)
</TD></TR><TR><TD>
Fire Point °C (°F) (ASTM D-92)
</TD><TD align=middle>
242 (468)
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Pour Point °C (°F) (ASTM D-97)
</TD><TD align=middle width=80>
-44 (-47)
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Noack Volatility (DIN 51581) 250°C for 1 hour, % weight loss
</TD><TD align=middle width=80>
8.9
</TD></TR><TR><CENTER><TD>
Four-Ball Wear Test (ASTM D-4172: 40kgf, 150°C, 1800 rpm, 1 hr) Scar diameter, mm
</TD></CENTER><TD align=middle>
0.44
</TD></TR><TR><TD>
Total Base Number
</TD><TD align=middle>
8.00
</TD></TR><TR><TD>
High Temperature/High Shear Viscosity, cP (ASTM D-4683)
</TD><TD align=middle width=80>
4.2
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