cog belt vs. smooth belt HJ61 landcruiser

Hi Figtree , I think you may find that the cogged type belts will only be of advantage on small pullies as the missing coggs if you wish allow the belt to go around a tighter circumference.The standard V belt would probably last longer on normal pullies as the layers of webbing etc are from inside to out side where as with the cogged belts only have a thin back bone. I think you will find most belts on vehicles only run around, at a guess somewhere around about one third of the pully 90 degrees which dose not require a flexible belt as in some engineering applications or where the belt only runs from one pully to another completeing a full 180 degrees on small pullies.
Hope you all can understand what I'm trying to explain if you do can you explain it back to me so i can understand to thanks
Steve West.