Regen braking can be dangerous on icy roads

[ASUN]

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.

 

[jadnashuanh]

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.

 

[prettig]

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]

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?

 

[prettig]

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]

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]

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]

I have a 2017 i3 with REX.

So far, no complaints with Winter driving.

 

[prettig]

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]

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.

 

[jadnashuanh]

If you're astute enough to turn regen off when you experience this sort of situation, you'd also be astute enough to feather the pedal...muscle memory would not help here as expressed.

Some people avoid taking their car in to get the latest software updates, but BMW has tweaked this aspect of operation on the i3, and it makes it less likely to occur. But, if you experience ice when you drive and you're not using winter tires, you're doing yourself a disservice. Consider them a form of insurance...you hope you never need them, but you're glad when and if you do. All-season tires are a compromise all seasons, just like winter tires may not work great when it gets warm out, all-season ones (and especially summer tires) lose a lot of capability when it gets cold or the roads turn funky with snow or ice. The group observation that the i3's all-season tires tend to wear out fairly fast may be a symptom that Bridgestone made them slightly softer to provide better grip when used in the cold weather...this is just a guess.

NH gets a lot of snow and ice is not uncommon...I hope I never see this problem, but so far, it has not been an issue in the now nearly 4 winters of use.

Anyone in say Norway or Sweden where snow and ice is a significant component of driving have any comments?

 

[AlexDP]

The new LCI ASC/DSC system should avoid this...

 

[MikeS]

What is LCI? ASC? DSC - dynamic stability control?

 

[theothertom]

What is LCI? ASC? DSC - dynamic stability control?

LCI = life cycle impulse which is BMW speak for a model refresh that occurs about mid cycle of a models life. Models usually last 7 years so since the i3 started in 2014 the LCI occurred with the 2018 models.
ASC/DSC refers to traction control. Your other BMWs have this as well.

 

[Milam]

My i3 does pretty well in the ice and snow

 

[EricC]

My experience in Seattle which only has a few snowy icy days a year is that the regen braking can be scary on even a modest, icy downgrade. Maybe I haven't learned the system yet to trust ABS/traction control. I'm on the larger wheels and no snow tires so I expect this doesn't help. Much as I like my i3 my wife's Prius w snow tires runs circles around it in the slippery stuff. I'd buy snow tires/wheels but have only another year on lease so not worth it.

 

[ASUN]

My experience in Seattle which only has a few snowy icy days a year is that the regen braking can be scary on even a modest, icy downgrade. Maybe I haven't learned the system yet to trust ABS/traction control. I'm on the larger wheels and no snow tires so I expect this doesn't help. Much as I like my i3 my wife's Prius w snow tires runs circles around it in the slippery stuff. I'd buy snow tires/wheels but have only another year on lease so not worth it.

You are not alone. It is a very very scary experience. Before you go down a hill, put the car in N, it will eliminate the regen. braking, so you can feather the brake pedal manually like a regular car for better control. Of course, getting a set of winter or all season tires will help. The summer tires are truly horrific on even slightly slippery surfaces.

 

[AlexDP]

The BMW i3s has Dynamic Stability Control with the functions familiar from other BMW vehicles. The only difference is that the BMW i3 is not fitted with a DTC button. DTC is turned on and off using the iDrive controller. The BMW i3 had previously also had Dynamic Traction Control. But this was limited only to the lower speed range up to 30 mph and essentially designed for straight-ahead driving. The DTC function was also modified when the new cruise control function was introduced in the BMW i3s for 11/2017. This means that maximum traction is available in the speed range over 60 mph and more drive power is permitted even when cornering. Special Automatic Stability Control has been developed for the demands of a highly dynamic electric drive. The control cycle works noticeably quicker than the previous ASC system. The ASC system also operates during recuperative deceleration of the vehicle and ensues that the deceleration can be maintained, even given difficult road surface conditions (rain/snow), and hence more energy can be recuperated. This results in improved stability, traction and availability of energy recovery in all driving and ambient conditions. In addition, an expanded and redesigned DTC mode ensures enhanced traction, particularly on loose surfaces and even more driving pleasure over the full speed range.

 

[jadnashuanh]

No car with summer tires should be driven in snow or ice. They don't work all that great when it gets cold, either. The difference between summer tires under those conditions and decent winter tires is like day and night. Think of them as insurance...you hope you never need them, but it's comforting if you ever do. There are places where driving without proper tires for the conditions is illegal, it's always kind of dumb. The i3 with the latest software is better than the original release. While I liked the stronger regen available on the first models, I can see where that could be a problem in messy conditions. The newest version limits max regen and adjusts how it is applied, giving you a lot more gentle reaction which is easier to control.

Don't feel bad, even in areas where snow happens a lot, the first couple of snowstorms of the season, people seem to have forgotten all of the skills they may have developed during the previous winters. Don't drive a car with summer tires in the cold or snowy/icy conditions...leave it at home. Any car. IMHO, the i3 isn't worse than most out there. If you've driven front-wheel drive vehicles for a long time, driving a rear-wheel drive car in dicey conditions is also a learning experience...best to attack it with the right tools.

 

[brorob]

If you're astute enough to turn regen off when you experience this sort of situation, you'd also be astute enough to feather the pedal...muscle memory would not help here as expressed.

My thought was for a way to turn it off before driving in these conditions, not at the moment a situation like this happens. And yes, latest software updates is important but irrelevant since mine had the latest software and my rear wheels would continue to stay locked up when testing this behavior on my secluded icy road. Obviously winter tires are a given but I didn't have enough in my budget to purchase this expensive option for this car. I have a winter setup for the shared family ICE vehicle (much cheaper) and would drive that when it was really bad, but had to drive the i3 on some snowy days. Leasing the car for 2 years was already a splurge on my budget.

Even a 'perfect driver' is going to have an "Oh ****!" moment when a feature like this would be helpful, no matter what software version you have or tires you're driving on. The car could even alert the driver when beginning a journey based on the built in weather app. "Roads may be slippery, would you like to engage Winter Regen mode?"

Overall, I thought the car drove great in the snow because of the tall skinny tires and low & evenly distributed weight. I even preferred the rear wheel drive in most situations. Even in normal snowy conditions the all season tires were manageable. It was just a few icy drives that felt unsafe because of the aggressive regen.