jadnashuanh
Posts: 4090
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: i3 is over

Sun May 27, 2018 9:33 pm

There is a need for a good city car...the i3 fills that bill quite well. If you need a more capable car, then while maybe the i3 REx could fill it, it isn't ideal. If the compromises are acceptable, it, too, can be a good car for some people. What the i3 is not, is a no-compromise, ICE replacement. We wont' see those until the battery tech gets better and the recharging infrastructure gets better. It's coming.

Long range is a crutch for many, but not necessary for as many people as they think. It would have been better if the BMW dealers in the USA all bought into the loaner program, but very few did. There are times when the i3 isn't going to cut it. If you could reliably get a replacement for those situations, it would be more viable as a single vehicle.
Jim DeBruycker
2011 535i x-drive GT, 2014 i3 BEV

Nyken
Posts: 32
Joined: Sun Apr 29, 2018 3:44 am
Location: New York

Re: i3 is over

Fri Jun 01, 2018 12:19 am

The thing I like about my 2017 Rex is the Rex: with Rex I have no range anxiety.

I have about 5000 miles on the car now and so far, I've used 2 gallons of gas in 6 months. But those 2 gallons were important to me, coming at the end of longer trips where charging was not convenient.

I can absolutely see a case for pure electric. Obviously Tesla drivers live with this. With my car usage, pure electric would need to have a range of 180 miles minimum.

So for me in my i3, the small gas backup is critical.

One thing I'm not so happy about is the heating. Since I live in the north east, heating efficiency and time to get to a comfortable temperature is important. So I can't understand why the heat pump isn't used to heat the Rex as it is in the Bev. Resistive heating is so inefficient, slow and underpowered.
2017 i3 Rex, Juicebox Pro 40

viking79
Posts: 107
Joined: Wed Apr 16, 2014 3:04 pm

Re: i3 is over

Fri Jun 01, 2018 5:39 am

Resistance heating is not slow, maybe for i3 it is (haven't triedyet), but my Clarity PHEV resistance heating is blowing warm by 3 houses down from my house.

The reason they use resistance heating in most PHEVs is it allows them to easily blend it with engine heat using the same heat exchanger in the interior.

I wrote a blog post about this:
https://carswithplugs.com/2018/03/17/el ... a-clarity/

jadnashuanh
Posts: 4090
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: i3 is over

Fri Jun 01, 2018 6:32 pm

I may be wrong, but I seem to remember that some of the hardware for the heat pump on the BEV sits in the area where the fuel tank of the REx is located. On a really cold day, the BEV reverts to resistance heating. Don't think that there's all that many other places you could put the gas tank, and the heat pump needs to be where you would be fairly close to the HVAC system to minimize the excess plumbing to keep weight and performance in check. Another thought, if you have the REx, the hit you take for using the batteries for your heat is more than overcome by the extra range you get with the engine. Nothing's free...Everything's a compromise.

Your best bet when it's cold, to set a departure time while plugged in, and get things preconditioned using line voltage verses all battery capacity.
Jim DeBruycker
2011 535i x-drive GT, 2014 i3 BEV

Nyken
Posts: 32
Joined: Sun Apr 29, 2018 3:44 am
Location: New York

Re: i3 is over

Sat Jun 02, 2018 1:15 am

Yes, I've used the BMW connect app to precondition this past winter. It works well on the days when it doesn't say "Car in motion" while it's in my driveway. :-)

While I'm not an expert at HVAC systems, my understanding of heat pumps versus air conditioners is that heat pumps have an additional set of valves to switch the flow of compressed gas. So I would not expect that the heat pump would be much larger than the current i3 air conditioner.

As for the efficiency of heat pumps versus pure electric resistive heating, heat pumps are much more efficicient. I used to own a factory building built in 1982 when electric was cheap. The building was 100% heated with heat pumps. You could never have heated the building with pure resistive heaters. But as the cost of electric rose over the years, as each heat pump unit needed to be replaced, we converted to A/C units with gas for heating.
2017 i3 Rex, Juicebox Pro 40

benjanos
Posts: 11
Joined: Sat Sep 23, 2017 10:30 am

Re: i3 is over

Mon Jun 04, 2018 7:57 am

Hi all,

I am not 100% convinced about the heat pump option on the i3. Let me explain what I have learnt and heard then I am super happy to have anyone correct me where I am wrong. Here we go...

The heat pump takes quite a while to produce heat and part of this time lag is energy being consumed as the system heats itself up. About six liters of liquid I think? Any instantaneous heat is coming from the resistive heater. So as you drive off in a BEV with a heat pump you are paying twice, heat pump plus resistive. I see in my car car on my short commute in winter (versus summer) the heating energy consumption is huge. Also in temps around zero Celsius the thing is not very efficient. So I am guessing the resistive heater is kicking in a bit anyway.

Since the i3 has such a low range, if I need to ‘stretch it out’ in any way I have all heating off. So at this point I am just carrying a heat pump around that is a) added weight, b) not fast to come online c) relies on a backup heat source that is already included. My solution was to by a nice jacket and not often bother with the heating at all.

Love to have some others thoughts
2014 BEV

jadnashuanh
Posts: 4090
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: i3 is over

Mon Jun 04, 2018 11:30 am

The heat is generated by compressing the gas, so that starts as soon as the compressor turns on...it does not need to heat up all of the refrigerant. It does take awhile for the heat exchanger to warm up, similar to the time it takes for it to cool off when in cooling mode, and the colder it is outside, the longer that takes for two reasons: there's less heat in the air to capture and the delta between what you're comfortable with and the heat exchanger is likely greater. Say it's summer. Body temp averages 98.6-degrees. Pretty much anything cooler than that will start to feel cool. Now, take it in the middle of a cold snap...the air may be zero, until it gets warmer than body temp, it will still feel cool. That amount of heat rise verses the drop during cooling will make it seem like it's taking much longer to start to do much of anything. In reality, it's starting fairly quickly. A heat pump won't produce as warm of air as say a 1000-degree heating element, or a radiator filled with coolant (which does need to all get warmed up).

Talking watts, a good heat pump can produce multiple watts of heat from much less energy to run it, unlike the resistance heater, which is 1 in, one out, the heat pump might be one in, 3 out or there about.
Jim DeBruycker
2011 535i x-drive GT, 2014 i3 BEV

GuyD
Posts: 21
Joined: Wed Jun 06, 2018 6:06 am

Re: i3 is over

Fri Aug 10, 2018 8:17 am

As a recent purchaser of a second hand i3 (BMW demo model - low kms; one year old; perfect) my thoughts are that there are few EVs around that are the equivalent - ground up sophisticated EV design beautifully made.

The 94Ah battery and Rex (which we've only used once!) gives us adequate range for 95% of our driving (but I'd still like more - 120Ah battery?) It is great around town and generally serves our needs very well. It will be supplemented by a bigger SUV EV when something becomes available (currently holding out for a Tesla Model Y)

We do have to do longer runs (within battery range) as we live out of town and this sadly shows up a few deficiencies - we also use it as an all-purpose car - dogs and big shops.

The suicide doors, sexy as they are, are actually just a pain most of the time and I'd trade four normal doors anytime!

But for me the biggest weakness of the i3 during trundling longer distances as a) the tyre road noise on anything but billiard smooth tar is beyond tiresome; b) the seats are far from comfortable and feel like they are out of place in such a classy vehicle (like a cheap Korean car?); and c) our i3 has nervous steering which requires constant supervision - hardly relaxing (I am getting the tracking and camber checked just in case...….)

For these reasons we'd not get a second i3 and I'd be cautious to recommend an i3 without some caveats.

jadnashuanh
Posts: 4090
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: i3 is over

Fri Aug 10, 2018 12:15 pm

One thing to consider...the 20" summer tires don't ride as nicely as the 19" all-seasons. For the slight potential improvement in ultimate cornering forces, that and the looks just don't tip the balance in their favor for me.

Tire noise is very dependent on how your roads are paved and the tires. Unfortunately, except for winter tires, there aren't really choices on the i3...maybe in a few more years the demand might justify someone making one. Given the nature of the design, long-term seat comfort wasn't a major factor. For typical EV range, I don't have an issue with it. My ICE is more comfortable on longer trips, and I choose that since the charging infrastructure around here is inadequate to even consider a timely long-range one. Those considerations also pushed me to opt for the BEV verses the REx...couldn't see the additional cost and lower efficiency worth it for my needs. I'm glad that I have the i3...it is fun, convenient, and less costly to run than my ICE on a day-to-day basis.

I'm hoping for a long-range hybrid that might get me my normal driving all electric, but without the inconvenience of trying to find a CCS unit working and available along my route.
Jim DeBruycker
2011 535i x-drive GT, 2014 i3 BEV

bwilson4web
Forum Supporter
Posts: 602
Joined: Fri Apr 29, 2016 11:59 pm
Location: Huntsville, AL

Re: i3 is over

Sun Aug 12, 2018 6:18 pm

Kiwi wrote:With the amount of long range battery Ev's being launched with great designs like the new Jaguar I Pace with a range of 480k who would pay the large dollars BMW requires for a very out of date BMW i3

Those who were alive in May 2016 when a Toyota dealer offered a 2016 Prius for the same price as a 2014 BMW i3-REx.

Bob Wilson
20k/27k mi 2014 BMW i3-REx
10k/10k mi 2017 Prius Prime

Return to “News and Main BMW i3 Forum Discussions”