Hill assist?

[nealeb]

Took the new A6 out for a test drive a few days ago. The salesman pointed at a button immediately behind the handbrake "switch" and said, "If you turn that on, the handbrake comes on automatically when you stop". I don't think he's quite right, but I can't find any reference to it in the brochure. My guess is that it's the Audi Hill Assist function, which apparently keeps the brakes on when you stop at a junction even after you've taken your foot off the brake. The idea seems to be that the car won't roll away before you've put your foot on the throttle.

Is that correct? How does it work in practice? Does it stop the Start/Stop function from functioning? Do you have to turn it off when you're manoeuvring in a car park? It was difficult to work out in an unfamiliar car, and I'm going to have to wait until mid-Jan to get my own one to play with! This was on a 3.0TDI Quattro S-Tronic, BTW.

[ianfarnham]

Yes, the main function of this supplementary button seems to be to automatically prevent creep when you stop - eg stationary and you take your foot off the brake.

To be honest this seems a bit of a curious extra which so far hasn't been used much by me or anyone else driving my car - but have only had it 3 weeks. When I get a spare half hour I need to try out all the combo's - there seems to be a heart gripping very small creep backwards when you stop on an up incline with footbrake on and the engine stops - when you release the footbrake the engine starts up but with a small drop back just before traction comes on again. You can hear the automatic brake operating but there is a fraction of a second with no footbrake, no electronic handbrake and no engine traction.

[nealeb]

Do you think that the slight drop-back is because the footbrake is locking the wheels while the handbrake works on the transmission somewhere? It means that there is a little bit of slack between the two. Or maybe it's because the footbrake locks all four wheels and the handbrake just the rear, so the rear suspension jacks up as you let off the footbrake? I seem to get the same effect when I stop on an uphill slope and put on the handbrake on my A6/C6. I've learnt to just let off the footbrake gently to take up the slack without any jerk - I'm a bit paranoid about everything being really smooth.

[ianfarnham]

I agree that if you are smooth and not too quick transferring from footbrake to accelerator all is fine and there is no slip back

[man le-mans]

I agree to be smooth and all will be good with no slip back. Have had to try it a few times in a multi-storey car don't think they get much more of a hill in them

[nealeb]

Another toy to look forward to playing with, anyway

[Blackmore Spur]

I have been using the button with great success on my two week old 2.0 TDi S Line manual A6. I really like the feature and find it works really well.....it automatically applies hand brake when I brake at lights or in queuing traffic, not just on a hill. Good news is it does work along with the stop/start function, provided temperature and other variables are in place (see the thread elsewhere on this site for more details about stop start function). When you turn off and park it turns off or if reversing using parking sensors....I turn it on when commuting every day now.

[ianfarnham]

Blackmore, I'm with you in that.

I've not yet worked out how hill assist works - id doesn't apply the handbrake as there's no familiar whirring from the handbrake mech on the rear wheels. that means it must either lock up the transmission clutches somehow or, maybe less likely, apply brake pressure via the hydraulics.

[nealeb]

I believe that the hill assist does use the hydraulics, as it's a feature that you find on Audis that have an old-fashioned manual handbrake, and with manual gearboxes. Seems to me to be the easiest way to go, and traction control means that the mechanics to apply the brakes under computer control are in there anyway. There are days when I know that the car is cleverer than I am...