When using the Diesel Power Tuning Modules, the increase in performance is very subtle. When giving slightly more pedal than you may normally, you will feel more pep and on hills you will notice the increase in torque. You will find less pedal change is needed to maintain constant speed as you climb the hill. It feels like your Sprinter glides up hills with less effort. This is not a lay-me- back, raw power, powerchip. Overall drivability is excellent especially with automatic transmissions. It takes very little getting used to.