I'd also thought about that... No doubt there would be less loss at 70mph and say 3000 RPM, than if vehicle were standing still but I doubt it's anywhere near one canceling the other...
got the petronix. have been using those guys since about 1997 or so. great points replacement for sure.
The video makes you wonder what a mechanical water pump vs an electric water pump results would be. One would think pulling and pushing liquid would take more HP than air.
Running underdrive pulleys on my '88 T-Bird with the Trick Flow headed 5.0 would gave approx a .05 - .07 sec decrease in 1/4 mi times... On the occasions I also ran a short belt to bypass the P/S, it'd pick up another .05-.07... With both mods, speed in 1/4 was also increased by a little over one MPH... It's commonly said for a street car, increasing MPH by a tenth takes around 10HP...
They wrote a test a few years ago in one of the magazines. Big difference between cheap parts store pumps vs good performance belt driven pumps. But not a ton of difference in a good belt driven pump and an electric pump.
I think I read the same write up...they said under drive pulleys can made up the difference. my 347 had an E-water pump and E-fan. I could get in my car and drive to Summits' exit (45 miles@ 75-80 MPH) before the fan would come on. I left the house one day and didn't get out of sight of the house when I noticed the temp gauge read 225 degrees...the E-pump bypass switch was off... it took less than 20 secs. at idle to cool down to normal temp (186) once switched back on...