Even my old Garmin GPSMAP60 has some interesting features. One is glide ratio.
You people might look to see if you have that feature and use it to test your Coupe's glide ratio at different airspeeds. I use the GPSMAP60 day-to-day in my car, wedged between my dash and the windshield, as a head-up-display of ground speed with the display set to large mode. It gives big, instant-reading numbers with accuracy to the nearest tenth of a mph. Ed
