Adaptive cruise control brakes too late

[TartanTsixer]

Help please with using ACC. When I first used it, it was on the default normal driving profile and it was okay up to a point but I found it brakes much later than I would. I changed the driving profile to Eco and it was dreadful - I didn’t once wait for the ACC to brake for me. I’ve tried changing the distance settings but they seem to make little difference and the pictograms of the cars don’t make sense to my brain so while driving I don’t know how it should be set to give me the greatest distance. Current settings below.
Anything else I can do to increase the distance between me and the car in front when braking kicks in?

 

[Jlo]

I assume you mean only when in normal driving mode and not emergency breaking? I just adjust while it's active, you move the image of the car further away, the image signifies the car in front of you.

 

[Oceanis]

Unfortunately, that is the way the system is tuned, mine is a late-braker too and it takes a bit of getting used to. It is worst if you approach a stationary set of cars at a high speed.

The advice from Jlo to increase and decrease the distance on the steering wheel buttons is sound - I do this too - the lower it is, the less likely you are at lower speeds to lose the target in front due to bends, hump-back bridges etc. So in slower moving traffic the speed remains locked to the car in front better when the distance is shorter ... but if the car in front brakes hard, you will too.

The other factor is the target speed, best not to have it set too high above your current speed because if the target car in front does disappear, then the system will accelerate quite hard and your closing speed on the next target will be that much higher, causing harder braking.

As to the settings ....

The "Driving program" really only affects the acceleration, e.g. eco accelerates slower to save fuel.

The "Last distance selected" check-box means that the car will remember the last target distance set for the active user profile, and it will use this setting again on next start-up.

The "Distance" setting is greyed out because you have selected "Last distance selected" ... if the check-box is not checked then the setting under "Distance" would be the default used on start-up regardless of the value on shut-down.

 

[TartanTsixer]

I assume you mean only when in normal driving mode and not emergency breaking? I just adjust while it's active, you move the image of the car further away, the image signifies the car in front of you.

Sorry I’m not sure what you mean by ‘not in emergency breaking’. These are just the settings I found for adjusting ACC. I find it brakes late when using ACC. I haven‘t ever experienced the van applying the brakes for me in an emergency braking situation. Thanks for your explanation of adjusting while driving. For some reason I find the pictogram really difficult to interpret. It’s probably really obvious to everyone else but it makes no sense with me. Do I keep pressing until all the white lines come on to make the distance longer?

Unfortunately, that is the way the system is tuned, mine is a late-braker too and it takes a bit of getting used to. It is worst if you approach a stationary set of cars at a high speed.

The advice from Jlo to increase and decrease the distance on the steering wheel buttons is sound - I do this too - the lower it is, the less likely you are at lower speeds to lose the target in front due to bends, hump-back bridges etc. So in slower moving traffic the speed remains locked to the car in front better when the distance is shorter ... but if the car in front brakes hard, you will too.

The other factor is the target speed, best not to have it set too high above your current speed because if the target car in front does disappear, then the system will accelerate quite hard and your closing speed on the next target will be that much higher, causing harder braking.

As to the settings ....

The "Driving program" really only affects the acceleration, e.g. eco accelerates slower to save fuel.

The "Last distance selected" check-box means that the car will remember the last target distance set for the active user profile, and it will use this setting again on next start-up.

The "Distance" setting is greyed out because you have selected "Last distance selected" ... if the check-box is not checked then the setting under "Distance" would be the default used on start-up regardless of the value on shut-down.

That’s really helpful, thank you. Your explanation of the target and current speed and why anyone might choose to have the distance set to near makes sense. I’ll uncheck the ‘last distance selected’ box. It is a skill in itself driving with ACC I think and I probably just need to use it more to get the hang of how the van responds. I used to quite like driving with the speed limiter with our last car, especially when going through roadworks so I’ll maybe use it more.

 

[Gavinda]

I believe the biggest issue people seem to have with ACC is thinking about it too much. I'd say the hardest thing to overcome is the fact that due to it being radar based it reacts to the closing speed where a person would react to brake lights on the vehicle in front, once you get over that and put a little trust in it you'll find that it's actually really smooth. I have mine set to the closest following distance and the most aggressive setting for speeding up as this most closely emulates how most of us drive ourselves.

 

[TartanTsixer]

Trust is definitely an issue! Thanks.

 

[JaiCee]

I believe the biggest issue people seem to have with ACC is thinking about it too much. I'd say the hardest thing to overcome is the fact that due to it being radar based it reacts to the closing speed where a person would react to brake lights on the vehicle in front, once you get over that and put a little trust in it you'll find that it's actually really smooth. I have mine set to the closest following distance and the most aggressive setting for speeding up as this most closely emulates how most of us drive ourselves.

I've always had mine on eco with our old VW Tiguan the closest setting was fine but with our camper conversion which is heavier it also breaks too late sometimes so we use the second closest setting.