This histogram charts the percentage of days that a Volt has driven a given number of miles. The green bars represent EV-only usage, and there are multiple options for the blue bars:
Total Mileage When Gas Used: If this is selected, the blue bars will represent the total distance driven when any gas was used. For example, if you drove 50 miles, 40 of which were EV powered, you would have a green tick at 40 and a blue tick at 50 in this mode.
CS-Only Mileage: In this mode, the blue bars will represent the number of miles driven in charge sustaining mode only. For our 50 miles/40 EV example, you would get a green tick at 40 and a blue tick at 10 in this mode.
Nothing - Show EV Only: Obviously, will clear the blue bars and only show EV usage.
In any mode, a day without gas usage will not get a blue tick. A vehicle's "day" is determined by the time zone of the zip code entered for the car. If the car doesn't have a zip code, central time will be used.
