People crack me up when they say how much power their motor made on the dyno.... but how much power is it making when you are using It? If you never go above 4k rpm, who cares what you make at 7k.
People are always amazed that I actually detuned my diesel truck to make less hp, but keep the same torque... It is very simple, it made it so I can get 1.5 mpg better. While that is not a lot, it does increase my mileage by almost 10%. On drive 60k miles a year, that's about 400 gallons of fuel. Or to put it another way, $1000a year more in my pocket. While not a lot of savings, every little bit helps and I am not giving the .gov as much money in taxes, which is always a good thing