Skotty
2014 S P85 | 2023 F-150L
I believe the Volt has a mode that effectively locks out the battery. Designed mostly for Europe you can charge at home then drive to the city on gas then switch to EV mode and drive in the city gas free.
So if you are going on a trip of more than 50 miles you can decide what part of the trip you want to be in EV mode.
This is called "hold" mode. It was added to US Volts in the 2013 model year I think. There were some questions about what affect hold mode would have based on regulations and such that may have delayed it's introduction in the US. I'm not sure there was any intent for it to be primarily for Europe.