The number on reason electric fans are used is because its difficult to use a mechanically driven fan on a transverse mount engine. Some cars actually have used hydraulic pumps to drive remote mount electric fans. If you look at most of the trucks and SUV's especially diesels, they still use clutch fans. A typical clutch fan can move like 8000cfm of air, electric fans can't even touch that without using so many fans that you are wasting money and alternator output. Electric fans compared to a straight driven fan do yield quite a bit of a power gain, but not compared to a clutch operated one. And for a race car that generally doesnt have an alternator fans and electric water pumps have significant gains, but not necessarily in street cars. In the next few years the OEM's will hopefully make the switch to 42v electrical systems, then high powered electrical devices will be more feasible. They are quickly finding out that 12v systems are just getting maxed out on cars today. 12v systems aren't as efficient because of the amount of current that must be used. It makes them heavier, run hotter, and draw much more current. It also hurts the durability of these parts. Once the switch is made, expect to see tons of electrical parts being utilized including water pumps.