The horsepower gains they advertise are going to refer to maximum engine rpm with a mechanical fan, probably without a clutch. If they test on a Mustang 5.0, they probably have it wound out higher than most truck engines ever see. At lower engine speeds, of course there is less drag.
I like my electric fans. It *feels* like the throttle response is better and a little more power. The A/C at idle (worst case for A/C sytem) blows cooler. In the winter, the engine warms up faster since the fans turn off. This should actually improve gas mileage overall, since the fans only work when they need to.
Whatever you do, it's either a lot of time or a lot of money, so it's really just up to what you prefer to run.
I like my electric fans. It *feels* like the throttle response is better and a little more power. The A/C at idle (worst case for A/C sytem) blows cooler. In the winter, the engine warms up faster since the fans turn off. This should actually improve gas mileage overall, since the fans only work when they need to.
Whatever you do, it's either a lot of time or a lot of money, so it's really just up to what you prefer to run.
