Todays engines are precisely controlled by computer and mechanically they are using lot of rather expensive race technology like 4 valves per cylinder, dual overhead cams, turbos/superchargers, etc. However they are designed for power at high rpm cause thats what Madison Avenue finds easiest to sell to peoples race car fantasies, even if the buyers will be sitting in 5mph traffic jam coming home with load of groceries. Few new car purchases are all that rational. I'd say its very rare for average car, even with an overhead cam engine to ever be used much above 4000rpm. And most engines if used much at high rpm arent going to last very long.
