Now you've confused them.

How?

I've managed to get my HCH into EV mode (not "electric only") fairly easily. Perhaps it's thanks to these warmer days. I keep an even pace on level ground or on a slight downhill. If the car takes the opportunity to force a battery regen, I put my foot gently on the gas and the IMA will come on, even though I'm still at 100mph on the instantaneous readout. This does not involve an Auto Stop of the engine. So long as I anticipate having an opportunity to do this before a regen opportunity (such as going down a steep hill, or braking for city traffic lights) I feel it will help bump up my overall mpg by a hair without severely draining the battery.

what do you mean not "electric only"? the situation you are describing is exactly electric only e.g. the gas engine is completely inert. it is not consuming any fuel and the vehicle is being propelled by the electric motor only. is there a different ev mode that you think the hch.ii can enter? just wondering.

I was on a deserted little road this weekend... went 1.4 miles in full electric mode at 25 miles per hour before I got to my freeway entrance. The battery SOC seemed to go down only one bar during the entire 1.4 miles. Would love to have tried a longer run!

The 2006 HCH does not have a true electric-only mode; it's an assist hybrid. The motor is technically capable of propelling the car without the engine, but the car is programmed specifically not to let it (unless you're totally out of gas); at most you can only run the motor at around 30% power, but even that is really difficult to do. And to do that, your eyes have to be glued to the gauges. A Prius, on the other hand, has a true EV mode and you don't have to look at the dashboard at all to stay in it (or to know when you're in it, for that matter).

When I mentioned it not running on "electric only", that was based on my experience. It appeared to me that the ICE appearing to still be running, albeit in the background and using only a tiny fraction of the gas it would ordinarily be using at that time. The energy required to maintain speed and momentum, however, appeared to be from the IMA batteries. If I've got this wrong, I apologize. I'm still learning and I appreciate all the information my friends here at GreenHybrid can offer. Thanks!

The ICE is spinning, but it is burning no gas at all. Same thing happens when you coast. The reason Honda did it this way is because it takes a second to spin the engine back up after it stops, which is unacceptable while driving, but acceptable (although annoying) when moving after a stop. So the engine is always connected to the wheels but the valves are sealed so it doesn't slow down the car much.

In contrast, full hybrids can move the car immediately via the electric motors while it waits for the engine to spin up. Plus the engine is actually rarely connected directly to the wheels as it's usually only used to generate electricity that heads straight for the electric motor.

depends on how you're defining "true electric-only". if by electric-only you mean the car is being propelled by the electric motor only then the hch.ii is definitely a true electric-only. the hch.ii switches in and out of electric-only mode seamlessly and often. one doesn't have to really look at the gauges. toyota's hsd is no easier to get into electric-only mode than the hch.ii in my opinion. neither car has the battery storage capability to keep it in electric-only mode for very long anyhow.

In order to activate electric-only mode in a Prius, gently press the gas pedal. The car accelerates forward without using the engine.

In order to do it in a Civic, you accelerate using the gas engine until about 25 miles per hour or less, making sure you're on a level or downhill slope, then you release the gas pedal and watch the instant mpg gauge until it hits 100. Once that happens (usually takes a few seconds), gently press the gas pedal as lightly and slowly as you can. Watch the gauges to see if mpg is still at 100 and you're using assist (white bars); if so, you are in electric-only mode. Keep watching the gauges so you know whether or not you're still in it.

Which of those two methods is the simplest? Only full hybrids can accelerate and go up hills in electric mode, and that's really the mode's main use -- doing things like shuffling through stop-and-go traffic, or going from stoplight to stoplight, etc., without ever turning the engine on. Cruising at a fixed speed without using the engine is fun but ultimately not very useful FE-wise because the engine does that efficiently anyway.