yeah i have a program that does it real quick and logs it on my phone with gas cost etc. I want to use the thing to see where i really get the best mileage at a decent speed without really doing the "trial and error" thing for a few weeks, since i drive close to 100 miles a day all freeway driving. If I get 31MPG at 65 or so I'll drop back from 75 instead of getting the 26 i'm getting now. I just want to know NOW! not a few weeks later lol