its like @joeymt33 said @Cook real hard to give u an answer the best way would be under full throttle to have a more consistent MARK. The unit has a throttle position sensor. All fuel injection vehicles do based on that it tells the ecu based on tps wheel speed and rmp when to shift. It also uses algorithms to determine rpm rise and at what rate it is rising so It can pre determine when to shift!! for instance if you are on the road under normal power and u hit ice and it starts spinning and u stay in the gas it will do 2 things in manual mode it will actually lower the rev limiter to protect the engine and in auto the ecu will prob shift early cause it see's a quick rise in rpm. the damn thing is smart!! for instance if u start it up and its cold It is in a limp mode map till it reaches full temp. So during that time the rev limiter is lower than normal and timing is retarded a couple of degrees for safety and it is throwing more fuel to warm it up. The amount of stuff that is in these ECU's is crazy. Me and some friends are working on an ecu editor to hack into it I cant wait! Did u guys know that some manufacturers put nitrous and boost controllers stock in the ecu,shift light controllers,2nd and third shift on the fly mapping,shift solenoid hold and delay times (notice how slow the shifts are when u hit the paddles) imagine hitting the paddle and bam super fast shifts up and down. Then flick a switch and everything is back to stock specs. thats all sport mode is (another map with different parameters and rules that can all be adjusted to your desire what ever that might be. That can all be adjusted its real safe right now all u have to do is access them they are already there. thats all power commander does they just make it easy to adjust fuel mapping but there is so much more there. change when your fan comes on and off change rev limiter per gear, shift points per gear, timing per rpm curve,duty cycle on fuel injectors (dry nitrous) no need for a wet shot! change Idle rpm,tell ecu not to down shift for you in Manuel mode, when unit is cold it has one map when its in normal operating temp range it has another, when its hot or to hot it has another when its in sport mode it has another and all those maps can be adjusted to your own parameters and pick between them on the fly, this stuff isn't for everyone just saying its crazy can't wait!!!