I have been reading up on nitro and petrol engines and some of them have 3 to 2 horsepower and stuff.Seeing that 746 watts=1 horse power,electric sytems(Castle Creations Mamba Monsters) easily pull 3000-4000 Watts.That is like 4 to 5 horsepower.So,is it the actual'capacity to do work' or is it somethind else?