Thank you for choosing Just Answer for your inquiry. My name is Allen and I will be assisting you. These trucks do have a vibration when coming in and out of the Multiple Displacement Systems operation. Yes when it goes to four cylinders. This is a common complaint by some customers thinking there is something wrong with the system but it is normal. Think of being in a four cylinder car or truck, don't they have a bit more vibration to them than a 6 or 8 cylinder? When they are new it seems more apparent. With more mileage the feature will still be noticeable at times but not near as apparent once the vehicle fully learns your driving habits.
The tow/haul switch overrides the system to keep it from activating and to keep it out of overdrive. Which in turn will reduce your fuel mileage greatly. If you need further information please let me know.\