ASUN
Posts: 131
Joined: Mon Nov 09, 2015 10:25 am
Location: Vancouver, BC

Re: Regen braking can be dangerous on icy roads

Mon Dec 18, 2017 11:41 am

prettig wrote:ok no problem, my car is 2013 REX but has the latest software and it went sideways for 10m on winter tyres.

I had to use left foot bracking, get the steering into the sliding direction and use to gas pedal to gain control again....... i was really surprised it did this and my "mother" would have driven into the streetlamp......
And yes very difficult to replicate, managed to do it once, problem is not snow it it snow and icy parts. As long as the tires feel grip it's really ok.
If all lose grip it is fast to correct.

But as soon as you steer in a bit and brake (regen) and the rear wheels are on ice and front in snow it will brake out.
It does detect it to late, abs does not work anymore (because it's going sideways, so not traction on the wheels).
I have personally experienced the above.

When we are in a dangerous situation, we are wired to immediately lift off the throttle and press on the brake. We are so used to having the car not braking for us when we lift the throttle. The regenerative braking is so aggressive in this car that it does cause it to lock up/slide the instant you lift off the throttle. This causes a lot of panic. It is a very scary experience, especially going down an icy hill. I ended up spinning out and hitting the curb. Lucky I did not hit any of the cars parked on the side of the road.

I must admit I got lost and ended up on this icy hill, and was driving with the summer tires. However, as per the above, even with the winter tires, I can assume that the car will behave the same way.
- ASUN, 2016 BMW i3 BEV, Arravani Grey, Suite Interior, 20's, since Oct 25, 2015

jadnashuanh
Posts: 5036
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: Regen braking can be dangerous on icy roads

Mon Dec 18, 2017 2:42 pm

The traction available between summer and winter tires in the cold/wet/nasty times of the year is day and night different.

At least with the software in my vehicle, it does not go into full regen when you lift off for about maybe 1/2-second or so, and ramps up to that point giving you time to get on the brakes. IF you're using the cruise control on a nice day...disengage it and see...it used to immediately go into high regen, but does not do that anymore, at least on mine. It may be that different markets, they use different software. But the first priority is to have the right tires for the conditions. If you hit glare ice, most any car is going to get to be a handful. A good winter tire will still have some traction, a summer tire won't. That difference can be a life saver. IF you can get some time on a skid pad, the experience is a good way to hone your skills and will help with any car you drive. That might be a parking lot before the stores open, or if you're lucky, maybe a track somewhere.
Jim DeBruycker
2011 535i x-drive GT, 2014 i3 BEV
Soon (hopefully!) A 2021 X5 45e will replace the above

prettig
Posts: 51
Joined: Mon Dec 11, 2017 12:12 pm

Re: Regen braking can be dangerous on icy roads

Wed Dec 20, 2017 4:39 am

winter tires make a difference BUT:
- same car same behavior, it does the same with winter tires it only will not happen as quickly

Like driving a car on a race track in the rain with slicks: it will slip easily.
Rain tires, it will do the same just not as quickly.
On dry track it will do EXACTLY the same if pushed more.
In all situations the car will behave the same if it looses grip.

jadnashuanh
Posts: 5036
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: Regen braking can be dangerous on icy roads

Wed Dec 20, 2017 2:47 pm

The common theme here is:
- don't push the car when the conditions are nasty; i.e., give yourself more following distance, drive slower, anticipate something bad happening, and plan an exit route constantly if someone or something happens in front of you. Winter tires will give you a bigger margin of safety, being the right tool for the job. Trying winter driving (unless say, in sunny SoCal) on summer tires is foolish, and gives you little margin for safety. Think of winter tires as insurance...it won't prevent problems, but helps should they occur. All-season tires are a compromise, all-seasons. IMHO, you owe yourself better. Some countries realize this, and make the use of winter tires mandatory. Our 'Live Free or Die' attitude (the NH state motto!) may be liberating, but not always sane! One has to (or should!) ask, what price freedom?
Jim DeBruycker
2011 535i x-drive GT, 2014 i3 BEV
Soon (hopefully!) A 2021 X5 45e will replace the above

prettig
Posts: 51
Joined: Mon Dec 11, 2017 12:12 pm

Re: Regen braking can be dangerous on icy roads

Fri Dec 22, 2017 1:32 am

don't push it ..... goes for every car in any condition....winter tires.... same for every car

Not the point here: it can lock rear wheels in situations it should not do it and create a dangerous situation.

prettig
Posts: 51
Joined: Mon Dec 11, 2017 12:12 pm

Re: Regen braking can be dangerous on icy roads

Sat Jan 13, 2018 2:54 am

ok.....no snow, but car just had a software update and regen now kicks in smoother ! (i had 2015 software, now 2017)

It has far more pedal play: letting go, first it will glide (not brake), a bit more it will brake a bit. Full off.....soft engages full regen....
Far easier to drive, not as nervous on the pedal and braking is way better to control (precise control).

It is like the first half off the pedal travel distance can be used to brake precisely, you have far more room to play with the pedal (and the same for accelerations).

And I have more range and improved steering wheel response.

Guess they did listen ......(I am sure it will be way easier to prevent the rear wheels from locking).

brorob
Posts: 104
Joined: Sat Oct 31, 2015 5:53 am

Re: Regen braking can be dangerous on icy roads

Sun Jan 14, 2018 9:08 am

I know the i3 is a great engineered car for the most part but it's disappointing when people chalk up this problem as 'you're a bad driver'. Yes there are bad drivers out there, I drive around them everyday, but I don't think people should automatically point a flaw in the car to 'it's not the car's fault, it's your fault'. I've been driving for 30 years, in snowy climates, and I know how to drive when conditions get bad. I know that I need to drive cautiously, allow extra space in front of me, etc. I've only had this problem a few times when it was icy out. While I've been able to control it after experiencing this scary behavior, there are moments when you need to react instantly in a situation and from driving 25+ years in a traditional ICE, my first reaction in a panic situation is to immediately take my foot off the accelerator. Is it bad driving when your instant reaction goes back to the way you've driven most of your life because muscle memory reacts quicker than your thought process, which tells you to NOT immediately take your foot off the accelerator because the aggressive regen braking may cause that ass end to slide out? There is a learning curve to driving this car, and muscle memory also needs to learn over time. If a deer or other animal runs out in front of me, muscle memory will win.

The point I made when I started this discussion is that a simple REGEN OFF button would make the car much safer in these situations. So maybe it would only be used occasionally but it would make me feel better when I leave work and the rain has frozen to ice. The fact that the ABS doesn't kick in is really disturbing. I've seen others don't have this issue so I'm curious why my car has this behavior. I tested this many times on my road when it was icy (private road with no traffic) and I could get the rear end to literally slide for several seconds and no ABS would control the rear wheels from locking up.

And yes, obviously winter tires are a given for driving safer in the winter, but if BMW is providing only 1 option for an all season tire, they should make the car safe to drive in all seasons using that tire. If this is a result of bad software code in some cars, they should address this.

Milam
Gold Member
Posts: 107
Joined: Tue Jun 20, 2017 4:03 pm

Re: Regen braking can be dangerous on icy roads

Mon Jan 15, 2018 8:47 am

I have a 2017 i3 with REX.

So far, no complaints with Winter driving.

prettig
Posts: 51
Joined: Mon Dec 11, 2017 12:12 pm

Re: Regen braking can be dangerous on icy roads

Mon Jan 15, 2018 10:16 am

brorob wrote:I know the i3 is a great engineered car for the most part but it's disappointing when people chalk up this problem as 'you're a bad driver'. Yes there are bad drivers out there, I drive around them everyday, but I don't think people should automatically point a flaw in the car to 'it's not the car's fault, it's your fault'. I've been driving for 30 years, in snowy climates, and I know how to drive when conditions get bad. I know that I need to drive cautiously, allow extra space in front of me, etc. I've only had this problem a few times when it was icy out. While I've been able to control it after experiencing this scary behavior, there are moments when you need to react instantly in a situation and from driving 25+ years in a traditional ICE, my first reaction in a panic situation is to immediately take my foot off the accelerator. Is it bad driving when your instant reaction goes back to the way you've driven most of your life because muscle memory reacts quicker than your thought process, which tells you to NOT immediately take your foot off the accelerator because the aggressive regen braking may cause that ass end to slide out? There is a learning curve to driving this car, and muscle memory also needs to learn over time. If a deer or other animal runs out in front of me, muscle memory will win.

The point I made when I started this discussion is that a simple REGEN OFF button would make the car much safer in these situations. So maybe it would only be used occasionally but it would make me feel better when I leave work and the rain has frozen to ice. The fact that the ABS doesn't kick in is really disturbing. I've seen others don't have this issue so I'm curious why my car has this behavior. I tested this many times on my road when it was icy (private road with no traffic) and I could get the rear end to literally slide for several seconds and no ABS would control the rear wheels from locking up.

And yes, obviously winter tires are a given for driving safer in the winter, but if BMW is providing only 1 option for an all season tire, they should make the car safe to drive in all seasons using that tire. If this is a result of bad software code in some cars, they should address this.
It just does (100% sure) and they know it, so they changed it (quite a bit), new software will make it much better. But I am unable to test (no ice).
Not just you.... lot's of post on the net.

ASUN
Posts: 131
Joined: Mon Nov 09, 2015 10:25 am
Location: Vancouver, BC

Re: Regen braking can be dangerous on icy roads

Tue Jan 16, 2018 12:22 pm

brorob wrote:I only had this problem a few times when it was icy out. While I've been able to control it after experiencing this scary behavior, there are moments when you need to react instantly in a situation and from driving 25+ years in a traditional ICE, my first reaction in a panic situation is to immediately take my foot off the accelerator. Is it bad driving when your instant reaction goes back to the way you've driven most of your life because muscle memory reacts quicker than your thought process, which tells you to NOT immediately take your foot off the accelerator because the aggressive regen braking may cause that ass end to slide out? There is a learning curve to driving this car, and muscle memory also needs to learn over time. If a deer or other animal runs out in front of me, muscle memory will win.

The point I made when I started this discussion is that a simple REGEN OFF button would make the car much safer in these situations. So maybe it would only be used occasionally but it would make me feel better when I leave work and the rain has frozen to ice. The fact that the ABS doesn't kick in is really disturbing. I've seen others don't have this issue so I'm curious why my car has this behavior. I tested this many times on my road when it was icy (private road with no traffic) and I could get the rear end to literally slide for several seconds and no ABS would control the rear wheels from locking up.

And yes, obviously winter tires are a given for driving safer in the winter, but if BMW is providing only 1 option for an all season tire, they should make the car safe to drive in all seasons using that tire. If this is a result of bad software code in some cars, they should address this.
I absolutely agree to the above.
- ASUN, 2016 BMW i3 BEV, Arravani Grey, Suite Interior, 20's, since Oct 25, 2015

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