Do the more expensive MPG Chips really work?

Question

For diesel engines?

what about Gas engines?

Im trying to plan ahead a bit here, It would either be for a Ford f250 or GM 2500 Vehicle.

Answer 1

I am guessing you are talking about a power programmer? Their are significant gains for diesel engines using a programmer getting better mpg and power. For gas the best thing to do is free up your intake and exhaust, I had my dad purchase the Fram Boost and also a 3" catback system from magnaflow and he saw an increase of 3mpg highway. Also mpg will improve slightly even slowing down on the highway by 5mph....