Depending on your settings, your PHEV may have the engine running to supply cabin heat. As a quick check on that idea, turn the HVAC off. That may not work if you also have auto defog enabled (which it is by default) as that needs heat and AC to work (the AC will be in stealth mode, the light will not be on). You can toggle defog with a long press on the front defrost button - a dialog will pop up and let you know which mode you just switched to.

For what it is worth, I toggled my auto defog to off shortly after I bought it and have never felt the need and the idea of running AC just feels wrong (one can still manually turn on the AC). And Hyundai/Kia is wrong for hiding that the AC is on with auto defog.

Typically unless it is really cold, I can manage any windshield fog with a bit of fan (just like the old days when I had no AC). Mind you, I have the HEV so no choice about engine coming on, so I'm covered after a few minutes in really cold weather with warm air to windshield. Which my car will experience for the first time tomorrow morning with a predicted 8F below zero.

 

Following to see what others have to say.

Haven't noticed the efficiency decrease while in EV mode, but I also never paid close attention either.

I gave up on charging the battery within a few months of buying my used '19 Ioniq last spring.

The cost of the gas for the distance (~30 miles) the electric battery charge would bring me is about the same. Not to mention, the speed of a gas fill up vs. 2.5 hours at the nearest EV charging station.

[My living situation doesn't allow for home charging (renting a room at someone's house - charging my car there could run up the bill and I'm unaware of any way to measure or compensate him for my usage).]

I will say that I absolutely LOOOVE my little '19 Ioniq. It replaced a beloved 2013 Prius C2 lost to a car accident. I was set on getting another fuel efficient car & it fit the bill perfectly. Seemed to have a far lower sticker price on comparable Ioniq PHEV vs various Prius options.

 

I charge at home for short trips but otherwise it’s HEV. I never charge away from home, for the short range it’s not worth it.

 

You should hear, your

 

You should be able to hear the combustion engine running. It starts up when you're heating the car's interior; when you accelerate more quickly; and sometimes just because - when the electronics seem to think the electric motor isn't sufficient.

The fact that the display shows the car is running only on electricity may be true. However, the combustion engine can still be running at idle, powering the heating or cooling.

 

However, the combustion engine can still be running at idle, powering the heating or cooling.

AC is powered by the high voltage battery, not the engine.

 

Here's a more technical explanation of what's going on, and the sort of mileage that you can expect as a result:

IONIQ Forum | So Canadians, how is winter driving with PHEV? | Reply #6