Heater Performance

I don't know.

I have remote start, which is nice if the car is outside and I want to pre-warm it. Of course, the AC is set to 72F, and that's comfortable, but I suspect I'd get more "heat" if I set it higher. It shouldn't matter. Cool or heat should be based on inside temp relative to set temp. The closer it is, the less the system works.

I do know some vehicles get hot enough to dry herbs in the cabin...like my pickup. Just the way it taps the coolant for heat. Cars typically don't do as well as trucks....at least until after they've been running for several minutes. Your Prius might do better if you can start it up and let it start to build up the heat before you get in and drive. In any case, it's a small engine it's drawing heat from compared to traditional ICEs and larger ICE setups.

 

I'd say the Prius is actually very fast acting. Were the Citroens diesel? If so, some of those have a preheater as diesel cars would otherwise take an age to warm up.

I keep my car at 20/21 all year round. What I have found is that if you leave the car on Auto then it waits until the car has warmed up a little before blowing the heat. If you want maximum heat asap then turn up the temp or at least set the fan speed manually. I usually put the windscreen setting on 22 and let the fan run high. The a/c also helps remove any moisture - stops the inside of the windscreen misting up.

You don't really want to investigate the extreme ways of getting a car to keep warm by blocking the grill etc as that's really for when temps are -10c or lower. Something I think is uncommon where you are

 

I live in NH where last winter we had many days in single digits (F). I had a Sienna at the time and I had to go about 5 miles on the highway before any heat started to come out When I got my Prius v in early March of this year, the temps were still pretty low and
I had heat starting in less than a mile. Of course, I also had on a heavy jacket, gloves and a hat and and a steamy container of coffee.

 

I live in North Dakota, one of the colder regions of the USA. When winter temps are fairly mild (0-- minus20C) I start and drive off within seconds, meaningful heat or defrost is 2 miles down the road and warm winter clothing is normal gear. During the cold part of a ND winter (minus 30-40C) I make a quick run to the garage, start the Prius with heater set at max, then make a quick run back to the warm house for 15 minutes. When I go back to the garage after the 15 minute warmup, the engine is warm and shut down, and just as important, the cabin is toasty warm for the trip. You learn to work with the climate.

 

The block heater speeds engine warm-up, which equals heat for the heater.

 

I've not noticed it being particularly slow but perhaps not as quick as some other cars. How long is it taking?
I think that to minimize emissions, the Prius prioritizes warming the engine up ahead of heating the cabin. Putting it on defrost might change that but I'm not sure.
It may also behave differently at different temperatures. 5C (40F) is very cold in Sydney but not in most of North America so most people here have different clothes and different expectations.

 

Grille blocking will help. Be careful about how much you block though. You can research those threads for more information.