As a new Volt Gen 2 owner I've been testing this gem in different ways. When I first put the car in Hold mode a while back, I noticed the slight hesitation known as chuggle. In later testing I noticed that Mountain Mode eliminated any chuggle I'd experienced in either Hold, or when the battery ran out in Normal mode.
So here's the weird thing. On a recent highway trip on Hold mode, I noticed that the battery was being used in conjunction with the ICE....just like Mountain Mode. I was on Hold mode at 72 km of battery reserve and this wonderful little car was cruising and accelerating as smoothly as a pure EV, using both battery and ICE. It was the same highway and similar driving as the previous tests.
So was I missing that before? Is that the way Hold mode should work? By both capping the battery reserve whenever Hold is activated, and then using the battery to assist like Mountain Mode? If that's the case, what's the difference between Mountain Mode and Hold Mode? Other than Mountain Mode reserving the battery at around 12-15 km.