Lexus22563

So I finally got my 350h premium about 11 days ago and liking it a lot especially the 40 to 41 mpg average I’ve been getting. Really like the infotainment system, remote start from my iPhone to name a few.
One thing I find odd is that when I’m parking , backing up or not lightly pressing the brakes I get a grabby sensation from the Brakes, like it is overly sensitive. Is this normal on a hybrid? How are your hybrid brakes?

Ihave1cat

Was your previous car a hybrid? If it was, did it feel the same?
the brake sensation of the NX is unlike any other car I’ve ever driven. The brakes are two-stage, regenerative (aka basically increasing a load in the converter-inverter assembly to act like a generator, this slowing the car) - and the good old regular brakes.
The synergy between these two systems make the brakes feel super grabby, and even feel like the ABS engages at times. It’s totally normal to feel weird, especially at lower speeds - if you’re never driven a hybrid before.

to answer your question, I felt the same, and it’s normal. But if you feel something is off, you can always ask your dealer to check it out!

Lexus22563

Ihave1cat
i had a Toyota Highlander which had really good smooth brakes. I know hybrid brakes are different. Just that when I park my NX in a tight parking space in my garage. I have to move in slowly and back out slowly. This is when I feel the brakes are not that smooth. The brakes feel kind of jerky or grabby when I press the brake. I find I really have to have a light touch. So I am wondering if others feel this when maneuvering this nx at slow speed. Do you feel this? Is this a normal thing?

Ihave1cat

yep! I felt the same! It’s like the car is slowing down because of the regen brakes, going smoothly, but then the actual brakes kick in, and that’s when you feel the jerk.
I came from a Honda CR-V, and the brakes there are much more predictable with regards to how much/constant deceleration.

NoMoreEv

My brakes seems to be good without the grabby feeling, but I came from a Tesla Model 3 which has a really strong regen braking.

Lexus22563

what about when you are slowly pulling into a parking space or when slowly backing out of a space. Do the brakes feel grabby or jerky to you?

Ihave1cat

that’s when they are absolutely the most jerky for me. My friend has also commented on the same. I’ve driven his car and I think it’s just how they are. I’m pretty sure it’s just the tuning of the brake balance between regen braking and normal braking. The stopping force of mechanical disk brakes is superior to that of regen braking, so the “jolt” of the system switching between the two methods is noticeable. My guess is that, as the car is brake by wire (correct me if I’m wrong), it’s basically two stage. The first stage is that the load on the converter/inverter assembly increases, causing the car to slow down based on trying to “spin the generator”, then, switches over to stage two - physical barking, which then applies the physical brakes, as the velocity of the car is not enough (not enough momentum) to allow for regenerative braking to function correctly. The transition from stage 1 to 2 is when the jolt happens.

of course there are also other factors, the amount of brake pedal depress, along with the initial velocity, proximity to other objects (potentially?) that affect regen-to-disk brake bias.

as one person pointed out (nomoreev) - the brakes are smoother on the Tesla 3, but that’s because it probably has a beefier inverter/converter which can tolerate a higher load and assist further with braking, plus, being strictly an EV, lacks the ICE, which may be better tuned to “crossfade” the systems in a wade that transition between them is not noticeable.

in any case, I believe this is normal.

Lexus22563

Thanks, It looks like you and I believe others get this brake sensation when moving slowly into and getting into and backing out of spaces. I feel better knowing it is not a brake problem.

dklanecky1

Interesting, on my test drive of a NX 350h last week, I actually commented to the salesperson how great the brakes felt, very linear and smooth, and at my age I've drive a LOT of miles.

I have no idea if there is any kind of setting that effect brake feel (or can even be set?), but it was impressive, and I was kind of looking for how smooth they would be for my wife, who is very sensitive to brake feel.

Lexus22563

The brakes and regenerative system works well for me when on the road. I am just seeing the grabby or jerky brake feel when slowly maneuvering around in a parking space.

based on a couple comments earlier this may be a normal thing

Ihave1cat

I want to point out that this is very circumstantial and noticeable in only very specific circumstances. When I test drove the 350h, it felt wonderful, heck, even driving around town feels great. The breaks are buttery smooth in most cases. The only niche case is when you're slowly crawling up or in reverse - like you're inching in a parking lot.
You know the feeling/sound you get when you drive in the winter, and the car has sat out for a bit, and the rotors oxidized, and you are pulling up to a stop sign, then stop, then let go of the brake, then brake again - partway, well that's when the brakes feel a little aggressive and grabby.
To address your concern - my wife often criticizes my driving, but has not commented on jerkyness. It feel jerky, but it's not too jerky.

twitte

The thing I noticed about my brakes is that the wheels lock up when braking hard. Since the car has an ABS brake system this shouldn't be happening. I don't feel any pulsation in the pedal that you normally feel with ABS. I know the car is heavy and will take longer to stop so I'm trying to allow more distance when in traffic. Anyone else noticed the brakes locking up on hard braking?

PS - Called my dealer. They will check this out for me tomorrow.

Ihave1cat

I haven't noticed, aside from the different brake feel, but there are a number of things that affect ABS in hybrid and EVs.
I was reading that aside from traditional ABS - Hybrid and EVs use PWM to brake. Perhaps given a slow speed, vector, and inertia, those factors, coupled with regen braking, causing the feeling.
https://aip.scitation.org/doi/10.1063/1.5031976
That being said, if you're ever concerned about the performance and integrity of your brakes, I would go to the dealer and have them check it out.
Hope that helps!

BC310

As another data point on a 450h+, which I imagine is similar, I agree about the brakes not feeling smooth/linear at creeping speed when parking. When I'm trying to creep up to a parking block/curb, the brakes do grab somewhat suddenly at a point when I'm gradually applying more brake pedal. Also when releasing the brake pedal slowly the vehicle jumps slightly. Neither sensation is really uncomfortable from a ride standpoint, it's more an issue of lack of control for precision parking. When parking super close to a wall or other objects in a garage, it makes it even harder to creep up as the Park Assist Auto-Brake can kick in too. I'm hoping I'll get the hang of it soon.

Brakes feel fine when driving/slowing and start/stop at intersections. Only comment there is regarding how the optional Brake Hold function works: I have to come to a complete stop and continue holding the brake for a second before the car takes over and I can release the brake pedal. When moving again out of a brake hold, some extra acceleration pedal is needed before the car will release. These are not flaws, just something to be aware of. Brake Hold works fine for intersections, but makes gradual creep acceleration challenging when parking in combination with what I describe in the first paragraph, so I have to disengage the Brake Hold function when parking.

I came most recently from a Model Y with one-pedal driving/full regenerative braking/brake hold. That car was much easier to learn how to control for parking and intersections. Though to be fair there were times that I had trouble with what would otherwise be normal coasting without brakes, plus the car seemed to brake/coast differently depending how quickly I lifted my foot off the accelerator.

DDGNX

Purchased 350h in April, brakes were very touchy at slower speeds especially. After 600 miles they seem to be better. Not sure if they needed a break in period or maybe I'm getting used to the sensitivity.