BMW to improve REx performance in North America

BMW is now working on a permanent fix for the issue the range extended version (REx). As some have noted here in the forums, under certain high energy consumption instances like climbing a long, steep incline, the range extender cannot continue to provide enough energy for the sustained period and the vehicle slows down so the REx can keep up with the energy demand. Here's the latest info on the modifications coming in a few months:

http://bmwi3.blogspot.com/2014/10/bmw-working-on-rex-upgrade-to-increase.html

TomMoloughney said:

BMW is now working on a permanent fix for the issue the range extended version (REx). As some have noted here in the forums, under certain high energy consumption instances like climbing a long, steep incline, the range extender cannot continue to provide enough energy for the sustained period and the vehicle slows down so the REx can keep up with the energy demand. Here's the latest info on the modifications coming in a few months:

http://bmwi3.blogspot.com/2014/10/bmw-working-on-rex-upgrade-to-increase.html

Click to expand...

Another joke from BMW on how to screw your customers. The Rex will engage early only if you use the navigation system and it says you will need it for you intended route. What a fucking bad joke adding insult to injury in my opinion. At least for me the only solution that does not steal from the non CARB state owners who get no benefit out of CARB bull shit is to allow us to engage the Rex at will as needed!!!!!!!!!!!!!!!

BMW rip off big time in my opinion!!!!! I am sick and tired of being screwed by big companies for their own financial gain!!! Screwed again.

BMW needs to get the message non CARB state owners are tired of being screwed by the CARB states agenda!!!!! YES SCREWED!!!!!!!!!!!!!!!!!!!!!
THIS IS BULL SHIT!!

HOW THE HELL DO WE GET THE REX TO ENGAGE MANUALLY THAT IS WHAT WE NEED TO BE ABLE TO DO IN THE NON CARB STATES! STOP THE BS.

I will bet there are many others on here that will agree but just wont verbalize it.

Take a deep breath and step away from the Caps Lock key.

You could always look into coding your i3 to enable the battery hold function. It seems to be working for some in the US.

Or you could try lobbying the CARB to loosen up a bit on the BEVx restriction that the battery has to be completely depleted before the range extender can switch on. Like it or not, CARB rules play a big role in the existence of all the EV's available now, including the i3. Without CARB we might not have the i3, or it would be even more expensive.

KurtEndress said:

Take a deep breath and step away from the Caps Lock key.

You could always look into coding your i3 to enable the battery hold function. It seems to be working for some in the US.

Or you could try lobbying the CARB to loosen up a bit on the BEVx restriction that the battery has to be completely depleted before the range extender can switch on. Like it or not, CARB rules play a big role in the existence of all the EV's available now, including the i3. Without CARB we might not have the i3, or it would be even more expensive.

Click to expand...

+1 Kurt. I believe we definitely wouldn't have the i3 or likely any other EV without CARB.

TomMoloughney said:

+1 Kurt. I believe we definitely wouldn't have the i3 or likely any other EV without CARB.

Click to expand...

Exactly two companies offer highway legal EV that are not subject to CARB-ZEV compliance:

Mitsubishi
Tesla

Other than that, nope, there likely wouldn't be ANY other EV's sold in the USA. GM would not have built the (hybrid) Volt without the successes of Tesla with the Roadster.

We also wouldn't have the upcoming surge of extreme limited production hydrogen cars from Toyota, Honda, Hyundai, and Mercedes (among others) without CARB.

Or you can get the BEV, and then there's no REx to complain/worry about.

I'm about to order the BEV, and I'll post why I think it's the far better alternative for almost everyone considering an i3, when I order it.

Surge said:

Or you can get the BEV, and then there's no REx to complain/worry about.

I'm about to order the BEV, and I'll post why I think it's the far better alternative for almost everyone considering an i3, when I order it.

Click to expand...

I encourage you to offer your reasoning Surge, but please understand, it's simply not possible for you to know who needs what. There are plenty of use cases that make the REx a preferable choice for many people. Yes, there will be some people that get the REx thinking they need it and end up realizing after 6 or 7 months that they may not have really needed it after all.

The REx is particularly useful in cold weather climate regions where the winter range may only be 55-65 miles, as some of the early European i3 owners here reported last winter.

I wonder if I can take any credit for this improvement: http://www.mybmwi3.com/forum/viewtopic.php?f=5&t=383

TomMoloughney said:

Surge said:

Or you can get the BEV, and then there's no REx to complain/worry about.

I'm about to order the BEV, and I'll post why I think it's the far better alternative for almost everyone considering an i3, when I order it.

Click to expand...

I encourage you to offer your reasoning Surge, but please understand, it's simply not possible for you to know who needs what. There are plenty of use cases that make the REx a preferable choice for many people. Yes, there will be some people that get the REx thinking they need it and end up realizing after 6 or 7 months that they may not have really needed it after all.

The REx is particularly useful in cold weather climate regions where the winter range may only be 55-65 miles, as some of the early European i3 owners here reported last winter.

Click to expand...

Tom, I agree and will post my thoughts in a separate thread.

The scenario you described is pricisely at the heart of my argument against the REx (in North American guise and in cold climates).

The reason being that the REx won't add much significant range. Using your example, you'd be at 55-65 miles of range in winter with a BEV.
So with a REx you would lose about 10%, maybe more, due to the higher weight and the less efficient heater.
So now you're at 50-60 miles.
Then add battey age, where with your 1 series I think you lost 10% after 3-4 years of normal driving. That's now a range of 45-55 miles.

And what will the REx add? Less than that due to the small tank, probably another 40 miles. Of course, the winter temp and the battery age affect the REx's ability to add range.

So I have paid 10% more for a car with 85 miles instead of 50 miles (remember the BEV has a longer range).
Is another 35 miles of range worth it?! I don't think so.

And I'm leaving out that the last 6.5% of batt with the REx involves running the gas tank dry, which is not at all good for the gas engine.

Surge said:

And what will the REx add? Less than that due to the small tank, probably another 40 miles. Of course, the winter temp and the battery age affect the REx's ability to add range.

So I have paid 10% more for a car with 85 miles instead of 50 miles (remember the BEV has a longer range).
Is another 35 miles of range worth it?! I don't think so.

Click to expand...

I would disagree with some of your figures, but taking them I've paid 10% more for a car which in summer and in winter will tackle occasional journeys which are effectively impossible in the plain BEV.

And, it will add 40 miles to the range, or 80 or 120 or 160 or 200... if I choose to refill the tank as needed.

For me the REX is the ONLY reason to buy an i3 rather than continue with the much better value Leaf we had for three years previously.

BrianStanier said:

Surge said:

And what will the REx add? Less than that due to the small tank, probably another 40 miles. Of course, the winter temp and the battery age affect the REx's ability to add range.

So I have paid 10% more for a car with 85 miles instead of 50 miles (remember the BEV has a longer range).
Is another 35 miles of range worth it?! I don't think so.

Click to expand...

I would disagree with some of your figures, but taking them I've paid 10% more for a car which in summer and in winter will tackle occasional journeys which are effectively impossible in the plain BEV.

And, it will add 40 miles to the range, or 80 or 120 or 160 or 200... if I choose to refill the tank as needed.

For me the REX is the ONLY reason to buy an i3 rather than continue with the much better value Leaf we had for three years previously.

Click to expand...

Agree +1.

The i3 as currently configured, works well for my situation, but the BEV would not work at all as I live in an area of very limited infrastructure and it is rural as I live 45 miles from a big city (Ohio).

Surge has always been way to pessimistic about range if you look back he is as obsessed with it as I am about BMW providing unhampered control of the Rex, my Rex with a full tank is currently showing 68 miles range and my i3 genius is telling me the range estimate software is going to be updated in the next revision because it is too conservative. I am getting 88 miles range in comfort mode with 50 to 60 deg F temps. and usually I exceed the range estimate which would indicate a range of closer to 90 to 91 miles usually (this is on battery alone in comfort mode). When the temperature drops my Prius plug-in drops from 14.5 miles to 11.9 in the dead of winter (last year) and that is about 18%. I am expecting my range to drop on the i3 by about 20% in the winter to about 67 or 70 miles and the Rex actually should not follow as the Rex output should not decrease just because of cold temperatures, at least I am not sure how that would happen or work with the way the system uses the Rex output. I know it is not direct, but immediate loss of another 20% due to temperatures just does not make any sense to me at this point.

I know I am obsessed with BMW and their implementation of the Rex in the US even though it does not really pose a problem for me here in Ohio, it for me is the purity of engineering as designed vs the government's arcane regulation and required bastardization of the hardware that aggravates me.

Mindmachine, I agree with you.

The ranges you are getting are very good, and that means the BEV range would be even higher. I understand why the REx makes sense for you.
However, if the drop in range due to cold weather is only around 20%, that is good news and further reduces the need for a REx (in my case).

Also, I do think the REx range would be affected by temperature. It's charging the same battery that is powering the car, of course. It's supplying electricity to a cold battery, so the capacity is still only 80% of normal, regardless of whether you're filling the battery or not.

The colder the weather (and also true on the other extreme), the i3 will spend more energy moderating the temperature of the battery pack to preserve its life and max range.

Ideally, you would be able to precondition the vehicle prior to leaving while still on the EVSE, and that would get the batteries and cabin into their ideal operating range without using actual battery power. A longer trip is likely more efficient than lots of short legs where the car has the chance to cool or warm up again, necessitating a bigger burst of energy to get things back into the ideal range for both the vehicle and the passengers.

John Higham, an i3 REx owner offered a comprehensive post for my blog elaborating on why he believes the BEVx rules that BMW is adhering to needs to be changed. It's long, but a pretty darn good read:

http://bmwi3.blogspot.com/2014/10/the-i3-rex-one-owners-thoughts-on-bevx.html

TomMoloughney said:

John Higham, an i3 REx owner offered a comprehensive post for my blog elaborating on why he believes the BEVx rules that BMW is adhering to needs to be changed. It's long, but a pretty darn good read:

http://bmwi3.blogspot.com/2014/10/the-i3-rex-one-owners-thoughts-on-bevx.html

Click to expand...

Great post on Tom's blog, even for a non-technical European reader, thanks.