Hi Trob, I always leave my go pedal on the sport plus +3. I enjoy the quicker responsiveness whether driving in the neighborhood, around town, or on the highway. I haven’t noticed much or any decrease in gas mileage, all the while also having my engine control module on at all times. It’s wild our Smart cars don’t already come with better throttle timing, in my opinion the go pedal is probably the #1 performance modification you can add for cost and benefit. You’ll never want to turn it off .