Good product depending on the make & model
Bought stage 3 for both of my vehicles. The results are as follow; 2015 Toyota Camry XSE 2.5L with CAI Better throttle.response, faster acceleration, higher shift points to maximize power, MPG increase of 3mpg when cruising 2007 Nissan Murano SL AWD 3.5L Slight increase in power and acceleration, no MPG gain.