All I want is to live next door to Martin, then I'll get a BMW i3!

Here in Australia, we've been using these for decades to heat & cool our homes. We call them 'reverse cycle air conditioners' as with a few valves, like in the i3, you can switch from cool to heat easily.

One thing really worth mentioning is that a heat pump system will increase in efficiency compared to a PTC heater the colder it is outside. Living in Sweden with long winters and often minus degrees the heat pump will use way less energy. England during winter is almost like summer ;)

The ultimate comparison of a feature that so many put on their wish list you have put a line under the answer is it really necessary, great work @wisely team.

I appreciate your attention to detail!

Great back-to-back comparison video.

Absolutely clear, great video.

Świetnie wideo! Dziękuje bardzo!!!

Great test! And love how you even weighed yourselves!

Only just discovered your channel Martin, already learned a lot I didn’t know about my i3s so thanks very much for the videos and keep them coming 👍

Brilliant, loved this episode!

Brilliant video, thank you so much for proving this point. I was expecting a slightly bigger difference in the result than this but knew it wasnt going to be substantial to how the car performs.

I'm in Ireland & because of our temperate climate I got my new Skoda Enyaq without a heat pump & haven't regretted it. I had one in my ID3 for 2 years & reckoned it was a waste of money.

Only came across the channel this evening, it's excellent and you have another subscriber.

Thank you for such a comprehensive video. When I ordered my i3, I did wonder about a heat pump. Now very glad that I did not bother!

That's a lot of useful information, thank you.

Another great and informative video! I wish there was a Wisely here in the US.

Thanks. Some very useful consumer advice.

Hi I was worried that I might be losing out by not having a heat pump but thanks to your in-depth vid I’m no longer worried plus mines a Rex anyway ! Cheers.

I really appreciated this video... lots of good comparison data. One variable was only briefly touched on in this comparison... environment latent heat level... in other words... ambient temperature. If the outdoors temperature is not significantly higher than the boiling point of the refrigerant, then there's very little the heat pump can do... there's just not enough heat to pump. It's when the ambient temperature is a little warmer - that the heat pump efficiency climbs much higher, yet the PTC efficiency doesn't improve. In climates where the ambient temperature is most often at-or-near freezing temperatures, the heat pump won't be much help. Also a static vehicle test completely removes the circulation of the ambient air around the outside heat exchanger. This means that the air in its vicinity is devoid of any heat, since it has been moved to the interior of the car. When driving, the heat exchanger always has an unlimited supply of air from which to extract heat.

great explanation of how heat pump works

Thanks for this comparaison ! It is always good to have the reality concept. I just swap my 94ah rex for a 120ah with heat pump, and on my daily drive i have some betters numbers for the heater. (already 4 degres here)

I've been waiting for this upload...! Fantastic back-to-back comparison of these 2 cars - really excellent number-crunching of the data. And a fascinating result - nothing like as big-a-difference as folks would have you assume, at least in this particular model. Great video, Martin & Arthur - lovin' your work, fellas...!! 💞

Hi Martin, greetings from Oxford. Fascinating video; I did not spec the optional heat pump on my 2019 120Ah, my thinking was in the Winter I would wear driving gloves and use the heated seats. In general this approach works quite well, misting up can be dealt with by the air conditioning, which drys the air entering the cabin. My Winter cabin temp is set to 17C in general, 18 for a treat! 🤗

Very interesting - thanks a lot!

Really clearly explained.

A really good test. I have a new Kia EV6 coming next month and when ordering the car thought do I have the heat pump or not. My decision was not to chose it at a £1000 extra I can buy a lot of electric for that money. Based on your test I think I made the right decision.

Awesome test, thank you so much 🙏

Thanks Martin, the Wisely i3 videos that you produce are so good and have helped me to appreciate what a great car it is. Having initially dismissed it as too quirky I am now sold on it and intend to buy one to replace our older 2nd car which we tend to use only as a runaround for local journeys and travel within our county. I would love to buy from you guys because of the care you take with preparation and because you are so honest about what you will do to prepare a car for sale, however you're more that 200 miles away so I think I will end up buying from a local BMW dealership and just have to hope that they are as honest as you guys.👍

Great comprehensive post...appreciated. Now to find an I3 which are rare in my area with even less to nonexistent for sale.

Love these guys. Great video, clearly explained, without dumbing down the detail for those wanting that. Please support them :) What was the app used?

Fantastic video..

Thanks Martin. Reminds me of golf equipment. Claims one ball goes farther or one driver hits it further, yet robot testing reveals that…yes the ball will go…2 yards farther or the driver the same. Big deal… Leased mine new in 2021 and at that time I think all US i3’s came with the heat pump in lieu of the gas generator. Still love mine. Charge in the garage as needed but only drive an absolute max of 100 miles round trip…ever.

I think the key measure is the cumulative power used by each of the two heating methods, particularly given that the heat pump actually uses more power than ptc initially, offset by lower use after a (short ?) initial period. For my typical use I have learned from you that a heat pump is only more efficient after about 20 mins use so only relevant to longer drives.

Really Nice video

Does any waste heat from the REX engine go into the heating system of range extender models?

Thanks, i love your videos

Interesting - so benefit from a heat pump configuration is mostly a higher speed initial cabin warm-up time, due to having both PTC and HP. If my sums are right, for a 94Ah BEV (like mine!) your observations translate to about 1 mile of range from the more efficient warm-up (e.g. warming up on a return journey without warming up on the charger), and then another 1.5 mile from driving efficiency. I did once arrive at a destination charger with less than 2 miles on the GOM so perhaps the heat pump made the difference there 😀but in reality I'd have driven even slower to reach the charger either way. The other thing interesting to see incidentally in your numbers, is the 17.13kWh at the charge versus 14.12kWh at the car - about 17% loss through the AC charger etc. So while I get 4 miles/kWh so 250 Wh/mile from my car, from charging at home it's actually more like 300Wh/mile or 3.3 miles/kWh.

I admire your commitment to the experiment! Fascinating that it's impossible to have a heat pump in a REX! Thanks for such an informative video. I will have to research the BT OBD adapter and app you are using - I'd like access to this information for my i3!

Outstanding 👍😊

Martin, well done on the vid. What's the app with the OBD2 readout from 2:30 onwards?

Makes me feel better about my 2014 i3 Rex.

Hi Martin, I love the video and I'm interested to know what OBD reader and App you were using to show all the information? I currently have an i3S (with heat pump) and would love to see the additional information shown. Many thanks, keep up the good work 👍👍

Is the performance of the heat pump vs PTC not a function of the outside temperature (at fixed cabin temp setpoint)? I would assume at cold temperatures (below 0°C) the advantage of the heat pump is reduced and at 10-15 deg outside temp the advantage of the heat pump is even higher. Anyhow, thanks very much again for the very interesting video :)

As ever really informative video, thank you. Curious to know what apps you were using. Come to that maybe you could do a video on apps in general relating to i3 and which if any you might recommend.

The difference between Heat pump and PTC is when you make a octo valve like Tesla. But otherwise difference is mainly in price.

Would you say the heat pump on the new ID5 would have the same efficiency? I have ordered one expected to arrive in the summer, so I can still add the heat pump option, but if it's anything like what you show here it doesn't seem like it's worth it at all.

Would the difference increase in favour of the heat pump car, when we are facing temperature og - 15 to - 20 degrees - like we do in norway quite a few days?

Very interesting to get some accurate real world results, according to the bmw service manual, the heat pump would need only half the amount of energy for the same energy output compared to the PTC heater. That beign said, the I3 unfortunatly does not recouperate heat from the drive motor, inverter or battery, these have their own cooling loop, and are not connected to each other in any way, the radiator for these components is behind the radiator for the heat pump as well, so no heat can be recouperated from this.

How would the heat pump be if you disabled the PTC heater? It would be much slower heating and maybe not work too well when its super cold, but wouldn't you get a more noticeable power saving? You would think there would be an echo mode that disables the PTC heater.

Your temps seem pretty warm to me. I would like to see a test here in Finland at -15 degrees, set two cars with preconditioning for the same time and drive as far as you can.

Great video, my I3 doesn't have a heat pump. Which app do you use on your phone for the data?

My results are with a Tesla SR+; 1 year with SR+ PCT I got 278 w/mile compared with SR+ with HP that gave me 243 w/mile over 1 year. Both cars travelled same distance of ~12,000 miles. That's over 10% better with HP, even though winter lasts only 6 months...

Hello! WHat app are you using? Is it for the OBD thingy? And holy cow! The preheat uses almost 6000watts! PS - Own a 2016 60ah i3 :D

Interesting test. So far, in my 2020 Niro, if I turn on the heater, it will supposedly draw 2kw, then after it gets going, around 600-800 watts. It's an air based PTC setup with heat pump. 40 seconds after it starts the heat is ready. Unlike this first gen setup, the Kia can harvest heat from everything. I wonder why GM and BMW here use a coolant based setup for PTC while Kia does it via a PTC/ ceramic heater style setup.

Keep it up

A great video to reveal the truth behind PTC vs Heat Pump. Very interesting because the Heat Pump has long been heralded as being a very significant improvement to an EV. Not so much it seems from your scrupulous tests and results.

Great video! I´ve recently bought an 2020 i3 with the heat pump system. I´m having a lot of difficulties heating the car up, it´s my first winter with it and the temperatures are around freezing. Usually the heating is turned on via BMW app before departure time, left to do it´s work for half an hour but despite the process cold air is blowing in the cabin😏 However, I've noticed that the cabin is heated (via BMW app) only when the car is plugged in and charging. No warning lights are shown on the broad computer. Any thoughts on the problem? Appreciate any help ty

Good video. A small comment: The heat pump itself is placed where the rex engine is mounted, so it won’t make any difference to move the petrol tank..

Great video. Do you see the HV PTC heaters failing much - out i3 2019 heater is not working, and wonder what might have failed?

Great information video. Having had i3 120ah without and then i3S 120ah with heat pump, I can say the biggest win I found for driving consumption was to pre-condition for my departure time while still connected to the home charger. As video notes, heat pump car took less time to be "ready" for me at 19C, and then the battery seems to reduce less quickly. Not nearly a scientific as Martin/Arthur's test of course, but sometimes observation and sentiment are important to owner experience too

However you may get a significantly better efficiency, if you preheat from a grid and then drive. Sustaining heat using a heatpump is substantially more efficient than using PTC. However BMWi3 with its low range it is indeed not a big deal.

I would assume the HP will be even more efficient if the outside temp is 10°-15°. But still negligible difference overall.

Off topic, but do you find the cars with the light coloured interior/steering wheel more distracting at night or in bright sunlight than the darker options?

My PTC died this past winter (120Ah BEV w/18,000kms) and the heat pump was unable to provide any heat whatsoever... no drivetrain warning either :(

Hi, whats the app that you use for the OBD?

Excellent debunk of the two heating systems. This clears the need to choose heat pump over the PTC. It also rekindles my interest in the REX.

When you do de test at 8 degrees Celsius I think de results for the heat pomp car wil be better, I have a I3S ...

Which App do you use for this measuring?

What app are you using to see those OBD specs?

Well explained, I have a 2019 Leaf with Heatpump and a 2023 MG5 with PTC heater My wife and I work at neighborhood Buildings, using the same parking lot. I’m curious how it will be next winter! - received the MG in June, no need to heat it

Btw, do I need to activate "AC" manually to get the heat pump running?

The test is a bit incorrect because for the HP it should be stopped after the car reached 22 degrees, because it had been waiting for extra 8 minutes while the PTC car reached 22 degrees

The most important decision criterion would be the noise made by a heat pump. My Skoda Enyaq is extremely loud and I'm just waiting for the neighborhood to complain. Mercedes does not even install a heat pump in the top model EQS and VW leaned too far out of the window with its promise and then had to make an expensive step backwards (see: kzfaq.info/get/bejne/fcp-fal5u9KdZqs.html)

Not really winter in UK unless you live in Scotland so won't show much difference around London's effectively heated streets!

The difference is negligible for most of the cases. Heat pump is just one more component to get broken. No need for additional complexity.

The BMW heat pump does not use the heat from the motors, like Tesla does. It would be interesting to know how much of a difference this makes.

With all respect something is wrong with data! 5.5 Kw for heat pump means the unit must have 7 hors power compressor and a huge condenser with the size of old Fiat 500! and it pools close to 80000 BTU! Even for electric heater you have the same huge numbers not matching with the size of the car cabinet.

Get a webasto ;)

I can't see which driving mode you were using for the test. I thought that Eco mode disabled the resistive heater and used only the heatpump. Comfort mode uses resistive heating and eco + uses no heating.

This is not good enough. Test it at -5*C while driving, no preheat. HP is more efficient at speeds.

Didn't know one of the worst cars has a following of its own, a small but a following nonetheless.