I think the guy's full of crap as well. E85 typically has around, IIRC, 80% of the energy of gasoline meaning right there you have a 20% jump in fuel consumption. So if the Mustang got 24 MPG on gas, doing the same thing on E85 would now mean 19.2 MPG. This is real; my customers with flex fuel cars complain about that all the time. So he's starting out with a 20% ass whoopin' even before he works his electronic magic. Of course, by now the oil companies have paid him off just like they paid off the guy with the 300 MPG carburetor. 
The problem with electric anythings on a car: the battery has to be big enough to store power for all the different items to work and that battery must be constantly recharged. That means the alternator has to be capable of enough amp output to run all the electrical accessories yet still have enough over capacity to recharge the battery and an alternator that big will still need quite a bit of power to operate. This can easily be seen by running a gas generator and then using it to operate a high amp draw device, the engine slows down and the throttle then opens to bring the gennie back to the desired RPM.
So you can cut parasitic draw by removing, say, the water pump drive from the drive belt system but you add back the power drawn by the alternator and now your parasitic draw savings is not so great.
Some of the drag race guys run everything (water pump, fuel pump, steering pump, etc) from electric motors to cut drag and do this successfully. The difference: they operate on a 'total loss' system meaning no alternator to draw engine power, the battery must be recharged after every run in order to keep all the electrics operating in the correct voltage range. That's one reason a lot of them run 16V batteries and they can get away with it since typically the time they are running the engine is measured in minutes.
