woohoo I'm a troublemaker
BTW I wasn't just in neutral. I was in drive holding the brakes to keep it from moving and using the torque converter as the load. So for an automatic trans that is the easy way to find out. For a manual trans I would suggest driving in a high gear and increasing the load going from holding speed/light throttle to wide open slowly (~3-5 seconds) and the gph value will stop increasing at some point. It doesn't show up on my tests till around half throttle so there needs to be enough load on the engine to keep it from accelerating faster than the display can keep up with.