Oil vesocity for 6.7 powerstroke
Looking at the specs for the 6.7, it says 10w30 for normal use. Also see that 5w40 synthetic can be used in severe duty apps. Has anyone switched over to 5w40 for normal use? Does it hurt to do so? I ...
Forum Discussion
wintersun wrote:
10W30 is the most commonly used grade for the fleets of big rigs on the road so no reason to fix what is not broken. A 5W anything is good only is the ambient air temperatures fall below zero degrees. They are not as good in temperatures over 90 degrees.
Sorry to pick nits here, but you clearly don't understand oil.
The 10 or 5 refers to the kinematic viscosity at 40*c, the 30 refers to the viscosity at 100*c. So, a 5w30 and a 10w30 are the same viscosity at operating temperature, measured in Centistokes, abbreviated cSt. The "W" means is certified for cold climates or "winter" depending on who you ask.
An SAE 30 grade oil will measure around 10-11 cSt at 100*c (between say 9 and 12 give or take), as will a 5w30, 0w30, or 10w30.
