[Ecky]

Adding power is generally not a way to improve economy. Hybrids don't get better economy because they add more electric horsepower / kw, it's because they downsize the gas engine and shut it off whenever possible, but keep total vehicle power the same with an electric assist. A lot of early American "hybrids" that simply slapped an electric motor onto the existing gas engine + transmission with minimal modifications don't get much, if any better economy.