Anybody have any experience with these? I have one and have a couple questions. I have been having some issues with unusually low mpg. I got the tuner to monitor and for better fuel mileage. Setting to economy the tuners gauges/numbers for mpg does not match the trucks gauges/numbers on the dash for mpg. Would the trucks gauges match the tuners because the tuner changed the program? It’s seems like if it was reading real time info to get these numbers they would be the same? I may be thinking about it all wrong for I know nothing about tuners. Also, do they tune the transmission as well?