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View Full Version : How does Start/Stop interplay with Stop-Go on the ACC?



Timothy Nathan
09-02-2012, 12:16 AM
The title says it all really. If the ACC brings you to a halt in traffic, does the engine stop?

BigAid
09-02-2012, 01:44 AM
Nope it sits there with the engine running. Acc turns itself off if the vehicle in front doesn't move in a minute or so - if you tab the cruise control stalk it will start following vehicle in front again.

If you put your foot on break heavily then acc turned off and stop start kicks in and stops engine until you reduce break pedal pressure to light touch - then think you can tab stalk to restart acc.

Will have a try tomorrow and see - I know acc won't kick in if vehicle in front is stationary - but not sure if you've had it on used stop start and tab it whether it will kick back into acc wait mode or will not work as you've a stationary vehicle in front until their moving and you tab it on.

Tbh not found it much of an issue as I mainly tend to use on Motorway or A roads not in towns - need to switch it off at roundabouts / slip roads as it leaps forwards as soon as vehicle in front goes out of field - and if your on a junction can tend to slow down if there is a car in the next lane queuing to turn right even if your road is open if they've not moved across enough......

Timothy Nathan
09-02-2012, 09:07 AM
My expectation is that I will only use it in motorway queues, but am really looking forward to trying it.

ACC was a major motivator to my getting a new car, and it having to be a new build (as it's almost impossible to find used in any marque).

I hope I am not disappointed!

nealeb
09-02-2012, 09:37 AM
ACC is one of those things I added to the options list for my replacement A6. I tried it on a demonstrator and found it very effective for relaxed motorway cruising. I've done a few long motorway journeys since then in my current A6 and often find myself in situations where it would make things easier. Not necessarily the tool you would use if you were trying to make progress, but if anything I find myself even more relaxed in this new car (always in E mode, which probably tells you something about my driving style:)) and ACC would add that extra icing on the cake. I have been warned already about using it right down to a halt at roundabouts - the saleman who set up that demo for me said that it had nearly caused an accident once for him...

I was wondering about the stop/start interaction as well. There are so many toys on this car that the manual doesn't really explain all the possible interactions between them!

BigAid
09-02-2012, 10:15 AM
I ended up with it as it was advertised as Audi Pre-Sense Plus on the vehicle - It's still all a bit new for the dealers I think they're moving pretty fast in the 2nd hand market if they're high spec which it has to be to have ACC added onto it - if they're not that switched on they'll not have advertised it with ACC - as the Pre Sense Plus package is the Side Assist, Lane Assist & Active Braking Guard which its well worth knowing if your looking for one with it.

I went into one dealer who didn't even know about the fog lights / lack of them in the lower bumper when the Lane Assist Cameras now sit........alright I might have researched quite throughly before test driving and wanted to see exactly what options were available but slightly crap when you know more than the guy selling them does.......

Generally do 1hr getting out of London in stop start then motorway cruising and probably do 25-35k a year and I've found it really useful - I used cruise control anyway and the new one goes in 5mph segments rather than 1mph segments but its ideal for when they car in front is continually adjusting speed. Also the default distance setting of 3 is a good 3 car lengths back - just annoying when your in a queue with the distance set and someone comes charging up the inside and undercuts you into the space......I do also wonder how it looks from the rear if you've accelerated above the set level and then stop and it drops back into ACC and slows the car down - I assume at this point that that your rear brake lights are on to let the driver behind know your reducing speed.

Only stopped working in the snow when the entire front of the car iced up....

I'm mainly in E apart from when I tab it into Sports if i want a bit of faster pickup when overtaking...

Edit: realised that sounds a bit harsh about the dealer I got the car from - it wasn't him there was a chap in a London dealership who I think must have been fairly new who's knowledge was a bit off the pace (and I've been driving A4/A6's for 7 years - having got to choose a new one about 5 years ago on the company i had a good look at what was possible with the allowance available) when I wanted a test drive / play - the chap i got the car from half way up the country was excellent - however the car was advertised with out a photo and i'd bought it before it even got into the dealers show-room based on the spec he was advertising it with what he'd got off the system. - The spec'd ones really do move fast.......which is why i had the nice surprise of expecting Xenons from the advert and getting LEDs - he didn't know about them as he'd not seen the car at that stage.

Timothy Nathan
09-02-2012, 10:25 AM
I agree that it's not impossible to find ACC on the second hand market, but if you have other requirements (mine had to be an estate, frinstance) it starts to get quite tricky.

People keep telling me that it's better to get a nearly new, or demonstrator, car, but my modus operandum has always been to buy new and keep forever (such that I am in my mid 50s and have only ever owned 6 cars since I was 20), which means that the depreciation is spread over the lifetime and you get exactly what you want.

nealeb
09-02-2012, 10:38 AM
if you've accelerated above the set level and then stop and it drops back into ACC and slows the car down - I assume at this point that that your rear brake lights are on to let the driver behind know your reducing speed.

I'm not at all sure that the rear brake lights do come on in those circumstances. At night, my high-level rear brake light is clearly visible as a vague red glow around the edges of the rear window, and I don't see that glow if I resume the CC and it brakes me down to the target speed. Just something to be aware of, I guess.


I'm mainly in E apart from when I tab it into Sports if i want a bit of faster pickup when overtaking...


That's when I use the paddles. The thinking is that that way, I'm already in my "overtaking" gear for when I accelerate rather than waiting for the gearbox to respond. It's a bit of a religious argument, though! One thing's for sure, and that is when you drop 2, maybe 3, gears and give it a bit of welly, you find out that it's not some lumbering old powered armchair...

BigAid
09-02-2012, 11:40 AM
Acc slows down, creeps forwards then stops about 3ft behind car in front and stops ACC go after 5 seconds - will sit there with engine running though - hard brake press then kicks the start stop in, light touch to take brakes off and restart in prep for heading off.

Lol - I've been utterly spoiled going from a 140 brake a6 to newer lighter quattro 3ltr - the 245 makes a Huge difference - pay for it in fuel mind compared to eco 2 Ltr - used to get 650miles out of the 70 Ltr tank on that

Get 480 out of new tank - really shocked until I realised they'd also shaved 5 ltrs off tank to save weight - was expecting to take a hit with 3ltr
& Quattro. Long term memory thinks avr 32.2 - 3819miles - first hour to do 10miles put of London to motorways kill it - get 40 out of London on motorways


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