Which Oil Grade do I Need?
My 2013 Ram 2500 Hemi has "5w20" stamped on the oil filler cap. However, the owners manual says to run "5w30" with a gross weight of 14,000 pounds. Well, the truck weighs about 6200 and the TT weighs ...
Forum Discussion
I'd use the 5w30.
You need to understand what the numbers mean to make an informed decision.
The 5 means the oil "performs like" an SAE 5 grade oil when it is at 40*C.
The 30 means the oil "performs like" an SAE 30 grade oil when it is at 100*C.
The oil has a higher absolute viscosity at 40*C than it does at 100*C as any oil does, but multigrade oil is less so.
Long story short, they feel they need the added protection of the 5w30 for hauling heavy loads when the 5w20 will be too thin. If you run 5w30 all the time, you will sacrifice a miniscule amount of fuel economy.
You need to understand what the numbers mean to make an informed decision.
The 5 means the oil "performs like" an SAE 5 grade oil when it is at 40*C.
The 30 means the oil "performs like" an SAE 30 grade oil when it is at 100*C.
The oil has a higher absolute viscosity at 40*C than it does at 100*C as any oil does, but multigrade oil is less so.
Long story short, they feel they need the added protection of the 5w30 for hauling heavy loads when the 5w20 will be too thin. If you run 5w30 all the time, you will sacrifice a miniscule amount of fuel economy.
