Such competition, of course, inspires questions of whether O'Reilly's in-house motor oil is any good ... including standard ...

It is a primary component of how SAE oil grades are defined (15W-40, 10W-30, 5W-40, 5W-30, etc.). Absolute viscosity is expressed as centipoise (cP). It is a measure of frictional drag within the ...

SAE 10W30 will sync with the components used in the vehicle. Any higher/ thicker grade(10w-30), might have constraints in the oil flow through the tighter tolerances maintained in the construction ...