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Braking Behavior

Low_Spark

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So today I was driving along and encountered a strange and potentially dangerous behavior with the 4xe braking. A car, several spots in front of me, forgot how to merge onto a freeway on ramp and created a bit of an accordion effect. I had plenty of room in front of me, I saw it coming, and I started to apply a little pressure to the brake pedal. In a normal car you press the pedal and it engages the brakes, with the 4xe its not always the case as it will first engage the battery regen. Well needless to say the gap in front of me quickly closed as the person in front of me came to a stop a couple car lengths shorter than they should have and I reacted by increasing the pressure on the brake. In prior vehicles this would have been sufficient, but the 4xe seemed to respond by increasing the regen resistance rather than engaging the brakes. Finally it got to the point that I had to abruptly press the pedal even further and it was like the computer decided "oh, you want to stop, OK" and the ABS kicked in and my AT's let out a moan as the contents of my passenger seat crashed down into the footwell. Thankfully nothing more came from it, but it is definitely something to consider while driving in traffic. Maybe its something that just takes time to adjust to, but I definitely get the sense that the systems dont always seem to be on the same page with one another.
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SpaceCase

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So today I was driving along and encountered a strange and potentially dangerous behavior with the 4xe braking. A car, several spots in front of me, forgot how to merge onto a freeway on ramp and created a bit of an accordion effect. I had plenty of room in front of me, I saw it coming, and I started to apply a little pressure to the brake pedal. In a normal car you press the pedal and it engages the brakes, with the 4xe its not always the case as it will first engage the battery regen. Well needless to say the gap in front of me quickly closed as the person in front of me came to a stop a couple car lengths shorter than they should have and I reacted by increasing the pressure on the brake. In prior vehicles this would have been sufficient, but the 4xe seemed to respond by increasing the regen resistance rather than engaging the brakes. Finally it got to the point that I had to abruptly press the pedal even further and it was like the computer decided "oh, you want to stop, OK" and the ABS kicked in and my AT's let out a moan as the contents of my passenger seat crashed down into the footwell. Thankfully nothing more came from it, but it is definitely something to consider while driving in traffic. Maybe its something that just takes time to adjust to, but I definitely get the sense that the systems dont always seem to be on the same page with one another.
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Echo4papa

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Nothing wakes you up faster than the barking of the tires on a Jeep when trying to stop suddenly!

Got to do that this past weekend somewhere just south of Baltimore on a long sweeping left curve from 29 onto 100 where the speed limit is 55 but the curve and trees conspired to hide the fact that traffic right around the bend was at a fucking complete standstill.

Luckily there was a car in the other lane just slightly ahead of me and I noticed them slam on their brakes, giving me a heads up. My wife was NOT alerted though, because she was fast asleep and woke up to the first real emergency test of the brakes in the 4xe.

I was impressed, and relieved.
 
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Low_Spark

Low_Spark

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Nothing wakes you up faster than the barking of the tires on a Jeep when trying to stop suddenly!

Got to do that this past weekend somewhere just south of Baltimore on a long sweeping left curve from 29 onto 100 where the speed limit is 55 but the curve and trees conspired to hide the fact that traffic right around the bend was at a fucking complete standstill.

Luckily there was a car in the other lane just slightly ahead of me and I noticed them slam on their brakes, giving me a heads up. My wife was NOT alerted though, because she was fast asleep and woke up to the first real emergency test of the brakes in the 4xe.

I was impressed, and relieved.
I'm definitely pleased with the Baja Boss A/T tire in this scenario... When the jeep finally decided it was time to stop, they made sure we stopped.

I hate curves like that, they need flashing lights to warm of slow/stopped traffic ahead.
 

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Getmadboy

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@Low_Spark I’ve noticed that braking behavior as well. Maybe I’m just not used to the braking distance on a vehicle as heavy as the 4xe, but having to come to a sudden stop has been a bit nerve wracking at times
 

omnitonic

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I hate curves like that, they need flashing lights to warm of slow/stopped traffic ahead.
I have to kind of chuckle at the thought. A similar kind of thing is this curve in my area that has a radar and huge ass flashing lights that come on when you trip the radar. WARNING! EXCEEDING MAXIMUM SAFE SPEED! FLASH FLASH FLASH FLASH FLASH FLASH FLASH!!!!! I don't know how many times I've seen people upside down in that curve, but it's a big number of times. Dozens? Scores? Scores of dozens? Probably the latter, as I've been driving that road for over 20 years. I'm pretty sure I've seen a few deaths in Dead Man's Curve. I know I've seen a lot of upside down vehicles. Especially 18-wheelers, but not exclusively.

Nobody pays attention to anything on the road except their damn phones. Wait? Did you say something? Sorry, I was busy playing Candy Crush while driving.
 
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Low_Spark

Low_Spark

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@Low_Spark I’ve noticed that braking behavior as well. Maybe I’m just not used to the braking distance on a vehicle as heavy as the 4xe, but having to come to a sudden stop has been a bit nerve wracking at times
It's definitely nerve wracking, makes me glad I have leather seats other wise there might be a stain or two.

I've thought about it more, and I really think it has to do with the computer trying to play match maker with the two braking methods. As long as it's consistent it will just be a learning/adjustment process, but if its no that is a real safety concern/issue.
 

Demonic

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I do sometimes have to press the brake more to get the wheel brakes to engage but I got used to it pretty quickly. The annoying thing to me is in the rain when the regen will cause the back wheels to slip before the disc brakes engage.
 

michail

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Is that feeling you landed on an aircraft carrier and caught the arresting cable?

I'm not sure if that is normal wrangler braking but my goodness, it sure can stop. From my understanding, regeneration works up to .25Gs, then the friction brakes assist.

My guess it it's just how they programmed the brake response and nothing about the regen specifically. Those friction brakes get plenty of assistance and have less chance of brake fade.

I've not seen stopping distance numbers but I'm curious how it compares. It feels like a high performance sports car, despite it's size.
 

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michail

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I have to kind of chuckle at the thought. A similar kind of thing is this curve in my area that has a radar and huge ass flashing lights that come on when you trip the radar. WARNING! EXCEEDING MAXIMUM SAFE SPEED! FLASH FLASH FLASH FLASH FLASH FLASH FLASH!!!!! I don't know how many times I've seen people upside down in that curve, but it's a big number of times. Dozens? Scores? Scores of dozens? Probably the latter, as I've been driving that road for over 20 years. I'm pretty sure I've seen a few deaths in Dead Man's Curve. I know I've seen a lot of upside down vehicles. Especially 18-wheelers, but not exclusively.

Nobody pays attention to anything on the road except their damn phones. Wait? Did you say something? Sorry, I was busy playing Candy Crush while driving.
I've watched so many dash cam videos I'm extra paranoid on those blind curves if I'm on the outer curve.
 
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2manyhobbies

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In the last 3 days, I have had an unusual experience with max regen. I was coasting, max regen on, and started braking. The “power flow” gauge showed the regen was probably 30-50% on the charge side. And then all of a sudden it went to zero, and it clearly was not working as “regen” - so I had to brake much harder to slow down.
This has happened twice. No error codes or anything, and my charge amount was less than 50% both times.
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