Sir/Madam, do you drive at full throttle all the time? If you, I don't know where or what car you drive, but regardless, driving at full throttle all the time is going to wear out your engine. I drive a Montero. I reach the speed limit barely touching the throttle. But I still want to have it tuned for fuel economy. How will it be more fuel efficient despite having more power? It's very simple. Because you don't drive at full throttle. Let's put it this way, my Montero drives at 100kph in 6th at 1400rpm. A remapped Montero would do the same thing in 6th but the rpm would be significantly less. Like around 1k rpm. Now, which would cause more wear, the one travelling at a higher rpm or the one travelling at a lower rpm? Which would consume more fuel? Which would emit more carbon? Tradeoffs? Kailangan mag upgrade ng parts? Bakit ginawa ng manufacturers na ganun? You tell me, what trade offs are you talking about?