saigopisetty
Posts: 2
Joined: Tue Jun 16, 2020 1:04 pm

Re: Anybody have an brake-related accident in an i3?

Thu Jun 18, 2020 1:06 pm

We have been driving short distances daily to drop kids and for groceries once in two/three weeks. Any suggesting on bringing this to BMW notice?

jadnashuanh
Posts: 5196
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: Anybody have an brake-related accident in an i3?

Thu Jun 18, 2020 1:28 pm

foggy69 wrote:
Wed Sep 13, 2017 1:05 pm
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.
Braking is a function of the tire footprint and the reason BMW went with the larger, narrow tire for the i3 is that it has less drag while moving, but can retain the same footprint as a smaller diameter, wider tire. Total footprint is a function of the vehicle weight and tire pressure. The wheel size will play a part in the shape of the footprint, but not the total size. On the wheel/tire combo in the i3, it is a longer one than wide, versus maybe a square or oriented width-wise you'd get with a smaller wheel. In reality, that might help in traction going straight for either starting or stopping, depending on the tread, and less for cornering.

Because we rely more on regen to slow us down, the brakes don't get used that often. They can develop a coating of rust, but also, if there's much of any gunk that got onto them, it doesn't get worn/scraped away like on a vehicle where the brakes are used constantly. That could affect the end result of your braking force.

The i3 still has a conventional hydraulic master cylinder, so the brakes should work even without power. The ABS unit can play into that if traction is reduced and it detects a wheel slipping, though.
Jim DeBruycker
2014 i3 BEV, 2021 X5 45e
(The i3 will be sold soon, <17K-miles, interested?)

jadnashuanh
Posts: 5196
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: Anybody have an brake-related accident in an i3?

Thu Jun 18, 2020 1:31 pm

saigopisetty wrote:
Thu Jun 18, 2020 1:06 pm
We have been driving short distances daily to drop kids and for groceries once in two/three weeks. Any suggesting on bringing this to BMW notice?
BMW will take notice if you file a complaint to the NHTSA. You can do that electronically on their website to report a problem.

Before I did that, though, I'd have a BMW shop take a look to verify that they see nothing wrong, and that any already discovered software glitch might need to be applied.
Jim DeBruycker
2014 i3 BEV, 2021 X5 45e
(The i3 will be sold soon, <17K-miles, interested?)

hollyakala
Posts: 1
Joined: Thu Apr 15, 2021 1:33 pm

Re: Anybody have an brake-related accident in an i3?

Thu Apr 15, 2021 1:44 pm

I just got into an accident in my 2016 i3 as I was starting to accelerate on a highway on-ramp.

After the initial curve of the road, I was surprised by the traffic meter light. A car was already waiting for the light to change from red to green, and I hit the brakes.

I hit the brakes really hard and they engaged but did not prevent my hitting the car. I get it, the distance was too short. But the car began to accelerate again, kept hitting the car in front of me, such that I had to keep hitting the brakes. It happened really quickly and there were no witnesses that could describe exactly what happened. Perhaps my car got caught on the fender of the Range Rover ahead of me. The airbags did not deploy.

The entire front panel/hood of the car was compacted and forced a crack in the windshield. The driver's side door was difficult to open, and the hood was sealed shut. The auto body shop is estimating repair costs near the sale value of the vehicle such that it will likely be totaled. I don't think I will replace my car with an i3 again, especially when I'm already having issues with the short driving range.

I am very disappointed that the brakes did not stop the car completely. Also, all parties have chiropractor appointments to deal with the multiple hits.

briantopping
Posts: 1
Joined: Fri Oct 16, 2020 6:56 pm

Re: Anybody have an brake-related accident in an i3?

Sun May 02, 2021 9:54 pm

I bought a used 2018 i3 from Green Eyed Motors in Boulder Colorado about seven months ago. I have worked on cars for many years and this car was in excellent mechanical condition with low (~18k) miles. They got the car as a lease return from BMW financial services.

Seven days after purchasing it, I was involved in an accident where there was some construction in the left lane of a two lane arterial with weekend shopper traffic. We were all going about 15mph to merge together and suddenly the entire line of cars put on their brakes. I was new to the car and know to put my foot hard on the brakes on an ABS car. Let the ABS figure out the right amount to do in order to stop the car, then modulate the brakes by backing off when there is safe following distance and time for the brain to catch up.

Unfortunately in this situation, the brake pedal went to the floor and there was clearly no stopping power except that of the regenerative system. If I had known this was about to happen, I had room to steer the car into the ditch and only affect my car. Instead, it ran right into the back of the car in front of me. The bill on the i3 was in the tens of thousands, the car in front of me had rear end damage as well.

I took the car to Gephardt BMW in Boulder and they went through it and said there was nothing wrong with it. The tech took me out for a drive and carefully put his foot on the brake to demonstrate how the ABS does it's job from 30+ MPH. As soon as I took the wheel back at the shop parking lot, I brought it up to 15MPH and stomped on the brakes. Same issue, the car kept rolling forward.

I bet I could reproduce it with any i3, but I was already committed to this car and who is going to believe you that "the brakes didn't work". Any time I tell the story, I get the eyeroll.

If anyone wants my contact information in a class action lawsuit, DM me. My insurance premiums have doubled and I lost $8,000 returning a car that I no longer trusted to the dealer after it was fixed. I think the insurance company deserves to see the truth as well so they can reconcile what happened.

Pahaska
Posts: 76
Joined: Thu Jul 30, 2020 11:49 am

Re: Anybody have an brake-related accident in an i3?

Mon May 03, 2021 9:22 am

I have had the same sort of hard stops in two different I3s (2017, 2019). The brakes worked perfectly in every instance.

User avatar
MKH
Gold Member
Posts: 787
Joined: Fri Nov 02, 2018 5:48 am
Location: Dallas

Re: Anybody have an brake-related accident in an i3?

Mon May 03, 2021 9:49 am

I just tried this in my 2015 - 15 mph and hard brake. Car stopped instantly.

Was the road wet? Gravel? The ABS keeps the wheels from locking up - if you were on a slippery or loose surface and slammed on the brakes, the ABS might allow some travel - but less than without ABS, because then you'd just be skidding on the slippery or loose surface with the wheels locked.

If not, a guess would be that when the brakes were flushed last, they botched the job and there is some air in the brake lines, or they weren't flushed at all, fluid was low enough that air got into the lines, and someone just topped up the fluid without flushing the lines. Because that statement you made "the brake pedal went to the floor and there was clearly no stopping power" is classic brake failure due to air in the brake lines.

Think about it - if i3s failed to brake at low speed during a panic stop, these boards would be so full of accident reports there would be no room for anything else, and the NTSB would be mandating a recall. I doubt there is an i3 owner in existance who hasn't had to slam on the brakes in traffic for accident avoidance.
Last edited by MKH on Mon May 03, 2021 6:16 pm, edited 5 times in total.
Mark H.
2015 i3 Rex, Capparis White, Tera World, Technology & Driving Assistant, Parking Assistant, Harman Kardon Audio System, 19 inch 427 wheels, EVoInnovate EVSE

agzand
Posts: 42
Joined: Tue Dec 22, 2020 3:00 pm

Re: Anybody have an brake-related accident in an i3?

Mon May 03, 2021 10:10 am

I think it is a good idea to implement a brake clean up cycle for EVs with strong regeneration (somehow similar to REX maintenance cycle). The car should detect brakes have not been used for a few weeks and disables regeneration for a few braking cycles to clean up the rotors.

I had a relatively hard stop a couple of weeks ago, I felt there was a split second of hesitation but once I pushed the pedal hard the car stopped instantly. When you have such a strong regeneration the brakes will feel different than an ICE car, you need to get used to it.

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