BMW i3: Heat Pump Comparison in Real-World Winter Conditions & Look Under The Bonnet

[@gymsaslan6625]

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 ;)

[@colinharvey1049]

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.

[@nitramluap]

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.

[@brianhydesmith2662]

Heat pumps / reverse cycle AC is not effective (on homes at least) when ambient temperatures drop below -10ºC or so. In my part of Canada, we set our car's interior heat to its maximum, from about November through April, controlling the heat with the fan setting. And there is no heat in most combustion cars until after they've been driven for a few minutes. Not sure whether the heat pump approach in cars would handle our conditions. At least it allows you to try heating up the car before you get in to drive.

[@12alocin]

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

[@MrGearoid65]

Absolutely!

[@rsc9520]

Me too !!!

[@beforebefore]

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.

[@briankldk]

Exactly… very good explanation that escapes most people when discussing heat pump or not.

[@wilkoone9155]

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.

[@simonreeves2017]

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! 🤗

[@andru9102]

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!

[@vremster]

Great information. Thank you. With my area being fairly warm year-round, and PTCs being more easily replaced, that's definitely my choice.

[@zcar4me]

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

[@richardstamper5630]

Perfect - well narrated and detailed. I even found out my i3S has a heat pump although I am totally convinced with it's efficiency Vs a PTC car.

[@jannuman7361]

Dear Wisely, hello Martin, Thank you once more for this very well presented and cristal clear explanation and practical test of the i3 heatpump option. I'm technical educated but I need all my brains to follow and understand all data. We can't ignore fysica of nature; it's all about efficiency. The Heatpump was a expensive option. I don't know it was worth that investment until the end of an i3 lifecycle. You have to be PhD in enginering or something equvalent. Otherwise you are a smart autodidact for sure. Excellent job! Grtz from The Netherlands.

[@Robert-yb3gm]

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.

[@francoismorainville712]

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)

[@derrickwroe7335]

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 👍

[@artysanmobile]

I would really enjoy and appreciate the very special i3 with range extender. For years, it has been alone in the market. An optimized hi-miler with a fuel tank the gas stations despise- my dream car. These are practically unicorns in USA, with our bizarre obsession for tonnage in our personal transports.

[@Mattchubb1]

Great test! And love how you even weighed yourselves!

[@stephenclay6852]

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.

[@Skyking6976]

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.

[@rhiantaylor3446]

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.

[@MrRossi1805]

Exactly my sentiments

[@stephenabbott904]

Great back-to-back comparison video.

[@TreDeuce-qw3kv]

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

[@wiselyauto]

Thank you! Where are you located?

[@TreDeuce-qw3kv]

@@wiselyauto Southern Oregon, U.S.A.

[@kevfquinn]

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.

[@happysporran]

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

[@wiselyauto]

Thank you very much! ❤️

[@ruaridhmccoll7229]

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.👍

[@wiselyauto]

Thanks for your kind words! These days the majority of our i3s are bought sight-unseen and get delivered, with an average distance of over 100 miles… so there’s really no excuse ;) Feel free to get in touch for a stocklist. We have circa 15 minute long HD video presentations of every car. Hope to hear from you soon! The Wisely Automotive team

[@ruaridhmccoll7229]

@@wiselyauto Thank you Martin. We are too far away, ie. more than 200 miles away on the S. Devon coast and you don't have a car that matches our requirements at a price that we could afford even if we were only a few minutes away. I have learned so much from your videos and would love to be able to buy an i3 from you but the truth is that we're going to have to take our chances with a local BMW dealership and hope that they're being as straight as you guys.

[@boomerang2]

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

[@wiselyauto]

Thanks! The app is called mi3.

[@boomerang2]

@@wiselyauto Damn, Apple only. Thanks anyway!

[@RobotoForgoto]

I appreciate your attention to detail!

[@maygarland6123]

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.

[@wakkadakkaify]

great explanation of how heat pump works

[@addictedtopiano]

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

[@wiselyauto]

Thanks! The app is called mi3.

[@andrewmorrish9381]

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

[@ryanjacques2007]

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

[@russellthomas3736]

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 👍👍

[@wiselyauto]

Thanks! The app is called mi3.

[@russellthomas3736]

@@wiselyauto Thanks, I'll get an OBD reader and download the App.

[@Whatshisname346]

Thanks. Some very useful consumer advice.

[@jonathantaylor1998]

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...!! 💞

[@SKraus-pb1ii]

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 :)

[@DannyThompson54]

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.

[@wiselyauto]

It seems to vary quite a bit from vehicle to vehicle, so difficult to just make a blanket statement. Really doesn't seem that important on the i3 though...

[@captain1664]

A great video. It all comes down to the design of the HP system, as your discussion of Tesla confirmed. It seems that BMW prioritise fast cabin heating, over maximising efficiency. Their system is also very simple compared to Tesla, so missing lots of opportunities to maximise the value of the HP.

[@sprockkets]

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.

[@benbaselet2026]

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.

[@neilmick6778]

I live at the south pole and would like to see a test at -50.

[@Internationalmanofmysteries]

I second this. I experienced -14,5° and later -20°c temperatures today and I was wondering about my heat pump staying completely silent. The car warmed up only via PTC and I was wondering if this is normal. Martin, if you know the cutoff point of the heat pump please confirm if this is normal.

[@wormsmaster1994]

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.

[@CandycaneBeyond]

Makes me feel better about my 2014 i3 Rex.

[@FranklySpeaking73]

Świetnie wideo! Dziękuje bardzo!!!

[@ksmith660]

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...

[@ChrisHaupt]

Awesome test, thank you so much 🙏

[@sparky3927]

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.

[@baercontact]

Brilliant, loved this episode!

[@rogerhudson9732]

Absolutely clear, great video.

[@NickLaslett]

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

[@Top12Boardsport]

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

[@CubbyTech]

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!

[@wiselyauto]

Thanks! The app is called mi3.

[@andreash.6841]

If you have an iPhone, you can use the app called "mi3". I use it in combination with a OBD II-dongle with wifi connection to the phone. Mine is a "Vgate iCar Wi-Fi" which works very well for me on my 2019 i3s.

[@manvsmachine1]

Hey guys I just bought a 2015 Rex and both heating and AC work fine when I’m not charging but don’t work when I am. Any ideas?? I can code whatever is needed. Worried about winter time.

[@paulf3353]

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.

[@RodLittle]

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

[@wiselyauto]

It's the heater itself which needs replacing. One of the most common claims on our warranty policy

[@RodLittle]

@@wiselyauto Thanks, I guess that's the ~£800 Electric Water Heater part that needs replacing?

[@wiselyauto]

@@RodLittle £864.38 inc vat to supply and fit

[@azlansharom7011]

Hang on… so the HP i3 has both a HP as well as the conventional heating unit? If so, do other HP cars also do this or are there HP exclusive models? If the i3 could be configured fully HP operation only, would it be more efficient?

[@wiselyauto]

Most EVs with heat-pumps feature both, as heat pumps can struggle to provide enough heat if the cabin temperature is set very high in very cold climates.

[@Steffenborge]

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

[@bjarkethanner9263]

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..

[@dave20thmay]

Not sure that you are correct. If you have no REX engine under the boot floor, then there is just a void, perfect for a WOKE boot extension. It is the fuel tank for the rex that is taking up the space for the compressor / heat pump.

[@nigelpentland]

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.

[@wiselyauto]

The app is called mi3. We definitely plan to cover apps and code reading in the future...

[@nigelpentland]

@@wiselyauto thanks for that. I’m an Android phone user although I do have an iPad. Looks sort of similar to one I just recently found on Android called Electrified (which I have to say I’m impressed with and like the look and feel of).

[@ranaockaili235]

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.

[@ThorEgilAarvik]

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?

[@ludwigreiser4053]

Very interesting - thanks a lot!

[@paulinchris]

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

[@wiselyauto]

Thanks! The app is called mi3.

[@RokoKaro-k8y]

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

[@wiselyauto]

It's likely to be a failed/failing Auxiliary Heater which will need replacing. Common, and independent to the heat pump system. Error code 801380 usually present in the car's logs, but not always.

[@Brinslade]

Really clearly explained.

[@markc6123]

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 ...

[@i3drivingnerd]

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 :(

[@sparky3927]

Well that answers my question about how good would it be without the PTC heater. I assume in your case though both the PTC and heat pump are not operating.

[@sandro5019]

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

[@shauno3429]

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?

[@wiselyauto]

The bright dashboard can reflect in the windscreen a bit more on sunny days but we never found it a problem to be fair.

[@1880.photography]

Fantastic video..

[@angelarodrigues2829]

Really Nice video

[@BMW-i3s-Denmark]

Thanks, i love your videos

[@wiselyauto]

Thank you! We appreciate the support.

[@thumper1747]

Outstanding 👍😊

[@MrRossi1805]

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

[@cheveredj8435]

My heating wasn't working in the cab so I've replaced the heating element but unfortunately I still have no heating in the cab, any information welcome thanks.

[@wiselyauto]

The heating is part of the HV system. We would strongly recommend getting the fault diagnosed by a BMW workshop or an independent specialist like us before undertaking any further work or throwing any further parts at it.

[@cheveredj8435]

@@wiselyauto it cost me £114 to get it diagnosed by a BMW specialist and I'm a mechanic so I thought ok I can fit this myself, I've checked for air locks and it's all fine I've plugged it in to texa and I've got no error codes but it's still not working, o well these things are sent to try us.

[@wiselyauto]

@@cheveredj8435 what was the result of the £114 diagnosis? If your AC is not running either (there should be an audible buzzing NSR of the car) then the HVAC fuse in the EME has blown. No error codes will show.

[@cheveredj8435]

@@wiselyauto hi thanks for getting back to me I really appreciate your time, the diagnosis was the heating element in the front of the car, the A/C is not working but I can't hear a buzzing noise, I'm going to take it down to work on Monday hopefully I can work something out👍👍

[@plamenpenkov6175]

super!

[@nigellucas560]

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.

[@christofchrappek5766]

Which App do you use for this measuring?

[@wiselyauto]

It's called mi3 - available on the App Store.

[@tutunmayan]

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

[@MegaPolarbear22]

What app are you using to see those OBD specs?

[@wiselyauto]

It's called mi3.

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: kzbin.info/www/bejne/fZWxe3l-i9FsbNk)

[@BobbyKouzmanov]

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

[@wiselyauto]

The app is called mi3.

[@SKraus-pb1ii]

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

[@benbaselet2026]

No that's just for the cooling.

[@SKraus-pb1ii]

@@benbaselet2026Thanks! That mean, if I turn on the AC when the outside temp is lower than the cabin temp nothing happens except for the LED lighting up?

[@benbaselet2026]

@@SKraus-pb1ii The AC can still be used to remove humidity from the air etc. so it will probably run until outside air is quite cool, below 10 degrees C usually. I don't know exactly how the i3 works, it would be interesting if someone had exact details. One way to watch it would be to check your power consumption via OBD while toggling the AC.

[@SKraus-pb1ii]

@@benbaselet2026 Makes sense. Thanks a lot!

[@glengosling5636]

Keep it up

[@TekAutomatica]

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

[@Garrison169]

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.

[@djtaylorutube]

I've never really thought the heat pump using more initially so less efficient for short trips. I have a Model Y so I'll have a play and do some simple tests. For a trip, it's certainly incredibly effective, typically the heating is around 1% of overall energy consumption.

[@dopiaza2006]

You didn't take into account that a 43% heavier person will generate more body heat too. I'm not sure how much more, but it won't be zero!

[@behrooz735]

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.

[@wiselyauto]

The numbers are taken from the official BMW training documents and are in line with other EVs. Keep in mind that with the i3 (and many other EVs), the AC is not only responsible for maintaining a comfortable temperature in the cabin, but also cooling down the battery.

[@rtarouca]

Despite your efforts for a well designed test and hard work, the test does not show how the heat pump is operating and at what Coefficient of Performance. Your test shows a very bad COP which can be either due to real world conditions or a heat pump with health issues. Because you said UK conditions would favour the biggest difference, there is the possibility that that heat pump could be malfunctioning.

[@parsl]

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.

[@wiselyauto]

We used COMFORT, but we can experiment with having them in ECO PRO in the future to see whether the difference becomes any more significant.

[@norwegianzound]

Is Londony innit.

[@tarassu]

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

[@tarassu]

Nissan Leaf with HP and without, difference is more than 20%. +5*C is laughable "cold".

[@RuzicaStevanovic-zs8vx]

Get a webasto ;)