Based on my experience with an OBD2 reader and the Android apps MyGreenVolt and Torque Pro and my 2012 Volt, the answer is no, you can’t just plug in a dongle and see a readout of your total mileage and ev mileage like you can using the OnStar and MyChevrolet apps or view on the MyVolt or MyChevrolet or VoltStats.net (if your Volt is registered there) websites. An OnStar Basic account or greater is needed to view your data on those sites.I'm thinking about picking up one of those OBD2 readers but wanted to know if I can get the total EV miles from that? I really can't understand why they don't show more details on the information screens in the Volt. I do understand that not everyone cares about the extra details but lots of people seem to be buying those OBD2 readers so why not just have a detailed stats page?
My understanding is that the MGV and TP apps can track and record daily ev distances driven if the dongle is plugged and the apps are receiving data as you drive (n.b., I use my OBD2 reader only occasionally). Daily ev distances, when added to the number of ev miles at the time you started to use the apps, produce lifetime ev distance. This number should reflect the same number obtainable from OnStar data on their apps or on the websites.
MyGreenVolt provides a configuration data file that can be edited to adjust for your current ev miles when you install the app. Bro1999 indicates that Torque Pro data can also be logged to track daily ev miles, which can then be used to obtain the lifetime ev miles.
These two apps do, however, provide a wide range of data on the Volt’s operation (such as cell voltage and battery SOC%) that are not available on the websites or on the car’s displays.