If you leave your G-tech on the dash for a long time. Heat may introduce drift in the Gtech's measurements. Don't worry, no damage will occur, but to check the unit simply hold it vertical. It's even easier to get performance times. The G-tech automatically stores and shows you your results after each run.
Operation is totally automatic.
The unit performed extremely well for us. With only an accurate weight input of your stang, a fairly flat level surface to drive on, and a proper placement of the G-tech in your stang, you can expect very accurate results especially after several averaged runs in your stang. Keep in mind that there are MANY factors that influence performance, engine temp, oil viscosity, wind, fuel, humidity, air temperature, driver skill, etc. Using the G-Tech, it would be best to use the same patch of road as well for your tests or a flat level surface each time. Find a closed area to do your tests.