Random braking

[Skyedriver]

Panamax said:

Having said that, some drivers seem to have a habit of touching the brake from time to time with absolutely no necessity. It's particularly noticeable at night when you're behind a car that brakes every time a car comes the other way. I think it must be a "confidence" thing.

Come around our way, particularly in the summer (tourist) months.

• Going over 40mph - brake
• something coming the other way - brake
• coming to a part of the road where it isn't actually straight - brake
• on a straight road longer than 400m - brake
• scenic view on left or right - brake

[Cats_pyjamas]

Robertb said:

SmithCorona said:

I think it's adaptive cruise tbh, many of them aren't predictive so seem to surge then brake.

Some systems are much better than others.

The problem is that no system as far as I know can see much further ahead than the cars in front and adjacent.

The distronic in my CLS is brilliant in 95% of situations but you still have to pay attention and react for best results.

I had distrontic on an e class 320cdi (lovely car). However it was useless on the A38, just too narrow and windy for it, it would brake with the outside lane clear, picking up vehicles on the left.

I've driven a few rentals similar, approaching for an overtake with good distance in front and as you pull out it slams the brakes on as it begins to pickup the car in front. I guess it's a learning piece on how the car reacts, but I am a stickler for leaving loads of braking distance between me and the vehicle in front.

[Zarco]

Skyedriver said:

Come around our way, particularly in the summer (tourist) months.

• Going over 40mph - brake
• something coming the other way - brake
• coming to a part of the road where it isn't actually straight - brake
• on a straight road longer than 400m - brake
• scenic view on left or right - brake

Its more likely this than any hybrid or active cruise shenanigans!

[Whataguy]

Pica-Pica said:

My 335d has that, when in eco-mode. It is on by default, but it annoys me, I prefer to have engine braking. Luckily, you can switch it off (and it will stay off, that is it does not come on again when you restart). The problem with default settings, people are not sufficiently interested to read the handbook and understand all these switchable modes of operation.

The annoying thing with many of the VW's I've driven is that there is no way to turn it off All you have is eco coasting in D mode or disabled in sport mode. And you have to manually switch on sport mode every time you start.

The 130hp 1.5 engine models are even worse. On those the engine actually shuts down completely when you are eco coasting... and eco coasting also happens when you are in sport mode on those models too, so there is no getting away from it.

[Whataguy]

xx99xx said:

Worked great for me, once you get used to it. Lift off in plenty of time and it will maintain momentum on a flat road for quite a while. Surely coasting at zero consumption is more efficient than accelerating until the point of needing to brake?

On the 1.5/150hp models eco coasting doesn't shut down the engine - it just idles at 1k rpm using fuel.

I believe if you are using engine braking the engine is using zero fuel? It may be why I was able to get 1mpg better in sport mode.

[Mad Maximus]

mac96 said:

Another possibility is hybrids; our X3 has no engine braking initially because as you take your foot off the gas it just maintains speed on the electric motor. You have to tap the brake to tell it you want to cut electric power as well as the ice.

That’s like the opposite way cars are now being programmed with one pedal driving. That would piss me off.

[mac96]

Zarco said:

mac96 said:

Another possibility is hybrids; our X3 has no engine braking initially because as you take your foot off the gas it just maintains speed on the electric motor. You have to tap the brake to tell it you want to cut electric power as well as the ice.

Our 2021 X3 PHEV doesn't act like that. It does vary the amount of regeneration if you lift off and coast. It's much more pronounced around town /sub 30mph where you can feel it slowing the car more, than on the motorway. It never maintains speed.

Perhaps there are different settings. Eco vs normal or whatever.

Ours is a 2022 model, perhaps slightly different.
I am not complaining, all in favour of economy, and can use sport mode when waiting to push on a bit.

[thecremeegg]

It'll be a mixture of EVs using regen, and radar cruise I would imagine.
My i4's radar cruise always wants to leave a HUGE gap and is always slowing me down if I get within 1 mile of the car in front

[Purosangue]

drmotorsport said:

Having racked up a few more motorway miles that usual recently i've observed what seems to be a strange new phenomenon. Driver/cars brakelights showing for no apparent reason. All appear to be newer cars both ICE and leccy powered, not a specific manufacturer and even seems to occur when they badly attempt to overtake someone, I thought it may be some be some kinda cruse control thing, but for the love of god it makes people look like incompetent morons trundling along riding the brake pedal. Any ideas?

its regenerative braking on the Mitsubishi PHEV which has 5 levels 1 being the lowest , if you switch to level 3,4,5 the brake lights will go on , its usefull if you have a tailgater , because they think your driving with your foot on the accelerator and brake

[Mr Tidy]

I was driving home from work in around 2012 and my Auto headlights turned on, then the tw*t in front of me decided to do a brake test.

I still don't understand why people seem to need to use brakes on Motorways - just look ahead!

[vikingaero]

thecremeegg said:

It'll be a mixture of EVs using regen, and radar cruise I would imagine.
My i4's radar cruise always wants to leave a HUGE gap and is always slowing me down if I get within 1 mile of the car in front

I honestly don't think it is EVs, regen or radarcruise. Most of the cars I see doing it are ICE cars. I honestly think it is down to the fkwittery of drivers these days.

Road sign on motorway, brake to read it. Sign on overhead gantry, brake to read it. Need to change lanes for the upcoming exit, brake. AA patrol on opposite carriageway with amber strobes on, brake to look. Incoming text alert, brake. Incoming social media message, brake, Passenger compliments you on your nails, brake. Passenger shows you a cute dog on her phone, brake.

[Robertb]

Cats_pyjamas said:

I had distrontic on an e class 320cdi (lovely car). However it was useless on the A38, just too narrow and windy for it, it would brake with the outside lane clear, picking up vehicles on the left.

I've driven a few rentals similar, approaching for an overtake with good distance in front and as you pull out it slams the brakes on as it begins to pickup the car in front. I guess it's a learning piece on how the car reacts, but I am a stickler for leaving loads of braking distance between me and the vehicle in front.

The adaptive cruise on my ‘05 reg IS250 was a menace. Used to brake hard when it picked up trucks in the inside lane on the motorway. The 2015 CLS has never done that and seems fine on corners, and does stuff like gently accelerate as you indicate to overtake, rather than braking as normal as you approach the car in front (though it will obvs if you don’t pull out!). You can set a big range of distance, and ‘override’ with the accelerator, for example if you can see a slower car in front is about to pull out of your lane.

My only criticism is in stop-start traffic mode, where it’s a bit too abrupt. Fine in crawling traffic though.

[Alex_225]

One thing I noticed having hired a few VW Sharans/Seat Alhambras for family holidays, the DSG in them liked to pop the car into neutral when you were off all the pedals.

Someone on here enlightened me to the fact that it's deemed that free wheeling and keeping momentum outweighed using zero fuel in gear.

That said, I'd find myself not losing speed anywhere near as quickly as you would in gear (the point I suppose) and I'd brake far more often than I would in my own cars. I did wonder how many other modern autos do similar and most drivers wouldn't bother dropping a gear to compensate. I'd often forget, find my speed creeping up over 70 on a slight hill and be slowing using the brakes.

[J4CKO]

Sometimes you get behind some nervous individual that brakes all the way down hills, brakes going over bridges or when a car comes the other way.

[Haltamer]

Probably guilty of this in places if you just looked at the brake lights, but there's usually a reason.

In the Jag (ZF8 Auto) There's very little / no engine braking unless you've manually dropped gears, so I often find myself giving little dabs or drags just in situations where I want the weight settled forwards a touch.

Also in the wet - Where there's visible standing water I'll usually brake it down then pick up again on the other side (Sane / No Aquaplane for me thanks) - Many seem to plow straight through.

I do see quite a lot of braking for fairies now - Probably due to phone distractions / google maps fathoming etc.

[Hoofy]

Actually, speaking of braking downhill, I noticed people braking as they go under intersections or down dips, and wondered why people were doing this rather than carrying the momentum to get them up the other side. It all suddenly makes sense. I'd be annoyed if my car started braking as I'm going down hill, doing 45 in a 50 like I see people doing on the A3!

[drmotorsport]

Interesting responses folks, I'm a subscriber to the brakes to slow, gears to go mantra - and so engine braking is not in my skillset I do however quite like the coasting feature in my 535i eco pro mode that essentially sticks the gearbox into neutral and the engine drops to idle if you come off the pedals for more than a couple of seconds. Personally I'd be mortified if my car was doing crazy stuff with the brake lights and annoying fellow road users behind me!

[Otispunkmeyer]

drmotorsport said:

Having racked up a few more motorway miles that usual recently i've observed what seems to be a strange new phenomenon. Driver/cars brakelights showing for no apparent reason. All appear to be newer cars both ICE and leccy powered, not a specific manufacturer and even seems to occur when they badly attempt to overtake someone, I thought it may be some be some kinda cruse control thing, but for the love of god it makes people look like incompetent morons trundling along riding the brake pedal. Any ideas?

I reckon its cruise control or adaptive cruise.

I notice on mine that the moment it registers any power in the "regeneration" direction whilst on cruise control, the brake lamps come on. This is different to when you're driving the pedal though where the brake lamps only come on when you're almost completely off the pedal. So you can be slowing down actually quite vigorously without the brake lamps coming on as long as you keep some pedal input in. Completely not the case when running the cruise control though!

So when I've used it coming home on a night, I can see in the rear mirror the guy behind getting lit up in red all the time. He must think I am an idiot.

There are a number of Tesla model 3 and Ys that I see on my daily route in to work and these cars seem to have it even worse as you can see their brake lights flicking on and off even when there is nothing much in front of them. I notice on one of the Y's that they must have some issue because their brake lamps appear to strobe a few times before coming on solid, then going off again.

At least with my EV6 when there is a clear road ahead it doesn't have any kind of phantom braking problem, but again it will put the lamps on if you're going down a hill as it regens to maintain the speed. I think that is probably a bit superfluous to be honest, but I guess when the "computer" is in control of the car, they want to cover all arses.

[Zarco]

drmotorsport said:

Interesting responses folks, I'm a subscriber to the brakes to slow, gears to go mantra - and so engine braking is not in my skillset I do however quite like the coasting feature in my 535i eco pro mode that essentially sticks the gearbox into neutral and the engine drops to idle if you come off the pedals for more than a couple of seconds. Personally I'd be mortified if my car was doing crazy stuff with the brake lights and annoying fellow road users behind me!

You never modulate speed using the throttle only?

[Whataguy]

drmotorsport said:

Interesting responses folks, I'm a subscriber to the brakes to slow, gears to go mantra - and so engine braking is not in my skillset I do however quite like the coasting feature in my 535i eco pro mode that essentially sticks the gearbox into neutral and the engine drops to idle if you come off the pedals for more than a couple of seconds. Personally I'd be mortified if my car was doing crazy stuff with the brake lights and annoying fellow road users behind me!

I've actually found I get better mpg not using the coasting function - perhaps it's because most of my driving is motorway, it might work better around town at slower speeds.

I did wonder about clutch wear on the auto gearboxes dropping in and out of drive when coasting, but VW has been doing this for quite a few years now and I haven't heard any issues.