Anybody have an brake-related accident in an i3?

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AlanDoc

New member
Joined
Sep 9, 2017
Messages
1
Hi,

I'm new here. I own a 2016 i3rex. I love this car and I love driving it. I've now even got over 'range anxiety.'

However I hate the fact that my first post is on a slightly negative note.

Before I bought the car the salesperson pushed in the wing panel and said "You can't dent an i3 - it just bounces back."

But my first issue was when I was forced to brake on a busy road. At the point where either my Golf or my Range Rover would have stopped -
the i3 kept going. However no problem this time.

Two months ago, in a rainstorm some body pulled out in front of me. I braked hard but the car didn't slow up in time and I hit the other car, a VW Polo.

The damage to the Polo? Some paint scuffing on the rear passenger door and a small dent on the rear wheel arch.

My i3? The entire front nearside corner burst open like tupperware. Both the front wing and the whole front assembly had to be replaced along with the lights. Luckily here was no structural damage but the bill (paid by my insurance) was £4,500.

Has anybody else felt their brakes are below par?
 
On the very rare occasion I have had to use my brakes they seem fine and no different from the X1 that I also drive.
 
Sorry to hear about your misfortune. It seems an anomaly. In the third party instrumented testing I've seen, the i3 has been better than average for small hatchbacks. Motor Trend magazine recorded 60 to 0 in 108 feet. For comparison, they got 118 feet in a 2015 Golf.
 
Did the ABS engage? If not, you weren't braking at the limit. If it did activate then it's quite possible there was a surface traction problem (diesel on the road, etc).

I've found my car stops as well as any modern car I've owned in the past 25 years.

Also, the dealer was an idiot to suggest that 'you can't dent an i3's panels' because you surely can... just like you can dent any other car's bumper/fender - it's effectively made from the same material.

The bodywork can certainly tolerate minor dingles better than a metal body, and is less prone to chips & scratches in this manner, but if you hit it hard enough (especially with a sharp object), it's going to deform and/or take a chunk of paint with it, and you might not be able to bend it back.

If the forces are great enough, it will shatter like a normal car's bumper. You *have* seen the i3 crash test videos surely? It's not bulletproof!
 
I've taken my i3 to autox and definitely felt the brakes could be a tad bit better. Could be just my worn tires/skinny tires but I find ABS engages rather easily.

That being said, C&D lists the 60-0 braking distance of 108ft. Comparable to many other sports cars. (104ft for the F80 M3)
 
I have not been that impressed by the brakes on my i3.
In an emergency, they seemed to lack the bite I expected. I assumed that the weight of the car and the narrow tyres are contributing factors.
 
foggy69 said:
I have not been that impressed by the brakes on my i3.
In an emergency, they seemed to lack the bite I expected. I assumed that the weight of the car and the narrow tyres are contributing factors.

Can't say I've needed to test them in an emergency... as I drive in a way that doesn't require me to.

When I received the car I did do a 'maximal braking test' on a closed road to get a feel for them. Seemed normal to me and the real data on the i3 suggests the same. The narrower tyres with a larger diameter result in a contact patch that is on par with the average entry level 3er, and the car is lighter... so I'm not sure what you're doing wrong.
 
IF ABS engages, your total braking distance can get huge. But, there are numerous reasons that might happen. As discussed, crud on the road that could include the diesel mentioned, but also oil, water, sand, gravel, snow, ice, etc. How new the tires are also makes a difference. The rubber is constantly getting harder as it ages, which lengthens the stopping distance and diminishes the grip. As mentioned, it's not the narrow tires as the contact patch is the same, and actually should be better than a shorter, wider tire...it is oriented along the typical direction of travel verses across it. But, if there's crud on the road, in that narrower path, length doesn't help.

Personally, I've found the braking response to be quite good. Some people drive with two feet, and it's my opinion that most people end up riding the brake at least part of the time when they do that...it's REALLY hard to hover over that pedal long-term. This can overheat things, and can glaze the rotors, which can also affect the braking distance and the longevity of the pads and rotors.
 
nitramluap said:
foggy69 said:
I have not been that impressed by the brakes on my i3.
In an emergency, they seemed to lack the bite I expected. I assumed that the weight of the car and the narrow tyres are contributing factors.
Can't say I've needed to test them in an emergency... as I drive in a way that doesn't require me to.
Do you drive at 10mph everywhere then, because however good a driver you are, however much you read the road and try to anticipate other peoples actions, things sometimes happen outside of your control.

nitramluap said:
The narrower tyres with a larger diameter result in a contact patch that is on par with the average entry level 3er, and the car is lighter... so I'm not sure what you're doing wrong.
As I said, it was an assumption about the tyre width, but the i3 Rex is over 400kg heavier than the not that much smaller Suzuki Swift Sport I had before. For a car, the i3 is very heavy. For an EV it is a bit lighter than the equivalent sized Zoe.

As for what I am doing wrong, I press the brake pedal as hard as I can when I want to stop very quickly, there is not a lot else I can do is there?
 
https://www.edmunds.com/bmw/i3/2014/road-test-specs.html
60-0 mph (ft.) 109

https://www.edmunds.com/bmw/m4/2017/coupe/review/
The M4's brake pedal is firm. The powerful (optional) carbon-ceramic brakes on our test car have excellent modulation and great stopping power. There are some groans at low speeds but that's expected. In a simulated-panic stop from 60 mph to zero, the M4 took just 106 feet, an excellent result.

So the M4 stops 3 whole feet better than the i3. !!!

Really, you might need a Ferrari or Porsche to have significant better braking than the i3.
 
Human error eat it I 3 is on front of every car of braking distance with 50/50 weight distributions and remember if you using regen for braking your i3 have rusted rotors you have to hit them hard once a day to clean them to be clean and keep them to a task to stop a car. They going to last much longer anyway then average gasoline car .if you don't feel those brakes go to parking lot and test them with hard braking to see how they perform 50 yrs of driving experience I3 owner 2014 watch for cars behind you b/c they heavier and they don't stop as fast as your bmw i3 skinny tires got nothing to do with stoping distance
 
I don’t think you need to ‘hit (the brakes) hard once a day’ as I understand that the i3 applies the brakes itself to keep the rotors rust free.
 
Self braking technology is not at least on my 2014 model and I believe not in i3 series recently I drove 2018 5 &3 series they were not equipped with self braking
 
MikeS said:
I don’t think you need to ‘hit (the brakes) hard once a day’ as I understand that the i3 applies the brakes itself to keep the rotors rust free.
Our 2014 BEV has very rusty brake disks. I am not aware of any automatic application of the brakes to keep the disks rust-free. When I brake, it is very obvious because of the grinding sound, so I'm pretty certain that I would be aware of any automatic braking. If stainless steel is appropriate disk material, I wish BMW had chosen stainless steel.
 
MikeS said:
I don’t think you need to ‘hit (the brakes) hard once a day’ as I understand that the i3 applies the brakes itself to keep the rotors rust free.

I don't believe this is true.

Great if it is though.
 
The brakes are automatically applied if the battery is 100% charged, the i3 is being driven and the accelerator is lifted (to slow the car). When the battery capacity is reduced, lifting the accelerator charges power into the battery without applying the brakes.
 
The brakes on any of this models of I 3 are mechanical brakes to stop a car you have to press a brake pedal you mixing regen braking when you not applay brake you able to slowly stop a car to stand stop when you take of a foot from accelerator once you perfecting your style of driving you really don't use a brake pedal that's why all this grounding sound came from bc rotors are rusty one day bmw is going to change those rotors bc they just nuisance stainless steal or at least zink coated
 
All BMW models include a brake drying function. When the windshield sensor detects rain, the brake pads are moved closer to the rotors to eliminate moisture thus reducing stopping distances. BMW USA posted a video explanation in 2012.

https://www.youtube.com/watch?v=VUwhCZ2duSk

The feature does not combat brake disc corrosion. In fact the i3 Driver’s Guide app (and owner’s manual presumably) states, “Corrosion buildup on the brake discs will cause a pulsating effect on the brakes in their response—generally this cannot be corrected.”
 
stumbledotcom said:
All BMW models include a brake drying function. When the windshield sensor detects rain, the brake pads are moved closer to the rotors to eliminate moisture thus reducing stopping distances. BMW USA posted a video explanation in 2012.

Yes, this.

I33t said:
The brakes are automatically applied if the battery is 100% charged, the i3 is being driven and the accelerator is lifted (to slow the car). When the battery capacity is reduced, lifting the accelerator charges power into the battery without applying the brakes.

The i3 still uses the motor for 'regenerative' braking even if the battery is full, rather than the mechanical brakes; it just doesn't go into charging the battery but it certainly helps run the consumers (ie. HVAC & battery cooling/heating). The display still shows kW being generated going downhill with a full battery and I can hear that the mechanical brakes are not being used.

So unless you actually use the brake pedal in the i3, you're not going to be wearing off the layer of rust from the discs. I make a point of using the brakes occasionally (once a week) to wear off the crud. I find doing it when exiting a motorway at high speed, and braking lightly for a few seconds, is more effective than trying to clean it off at slower city speeds and it doesn't kill the speed quite so quickly.
 
Has BMW changed the method?

I initially accepted that the brakes were not used, but I was corrected:

http://www.mybmwi3.com/forum/viewtopic.php?t=2298

We live up on a hill. When I drive down with 100% battery, I can hear the brakes grinding, and I rarely use the brakes on the i3. Yet there is noticable wear on the front discs since 2014.

If it is not the brakes, what is making the front end noise just like brakes when I back off on the accelerator?
 
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