10w40 Brad Penn. Also use Brad Penn break in oil on new engine break in.
The "w" stands for winter. The weight in this case is 50.
I looked for the 20S/50 for Summer but couldn't find it.
A future in management awaits you !
Really no need for all that. Everybody learns stuff for a first time. Lots of people KNOW what it means but still call the W meaning winter. We did everywhere I ever worked down here. We knew what it meant, but it was easier to keep up with it that way. Lots better ways to let somebody know they're mistaken than makin um feel stupid.
Flat tappet cam?
Zinc additive?
20w stands for the Low temperature dynamic viscosity while the 50 stands for the High temperature specifications.
http://www.ideas4ag-ed.com/uploads/...toepfer_understanding_motor_oil_viscosity.pdf
With viscosity improvers added to thicken it up when it is not hot.20w50 is only 20 weight oil...