I have a Ford PHEV, and it never kicks on simply due to speed. If you accelerate very sharply it will turn on, but that almost never happens in my experience. A

I have a Ford PHEV, and it never kicks on simply due to speed. If you accelerate very sharply it will turn on, but that almost never happens in my experience. And there is nothing that I'm aware of that causes it to use gasoline in order to prevent it from going stale. It is not remotely like an exaggerated version of auto stop/start. You have control over EV-now, EV-later, and automatic settings. Some PHEVs are stingier on the EV-limited top speed, but in my Ford I can go with the flow of traffic on 280 without triggering the ICE.