Quote:

A Group III synthetic should drain off less than a Group I/II dino or a Group IV (PAO) synthetic. Most commonly available OTC synthetics are Group III oils.

See BITOG Reducing wear at startup on a low service engine



That’s a pretty broad generalization.

A good starting point in any motor oil is the quality/type/amounts of base oils and complementary additives used in the oil as well as the know how in formulating a balanced lubricant.

Not all Group II, Group III, and Group IV motor oils are created equal. Some perform better than others and in some cases its application specific as well.

In the end, the trump card to determining a motor oils performance is with a Used Oil Analysis (UOA) report.

There are many Group II, Group III, and Group IV motor oils that return outstanding wear numbers in UOAs.

As mentioned, supporting data can be found at BITOG