I recently found this iEV app in the AppStore. I bought it and did use it to record some of my daily commutes and drives. However, the results are pretty inconsistent and mostly way higher than my own calculations. First I made sure to have a good GPS signal by using a TomTom car kit with integrated GPS antenna. I used the known parameters from the Model S (cd=0.23 , A=2.5 m² , m=1900 kg). Did anybody else test this app? If so, what are your results? If a roadster owner could verify ... but unfortunately the app is not free. So I don't expect a roadster owner to buy it. Thanks.