Adaptive Cruise Is this true Article in Courier Mail

[Hillbilly]

In the motoring section today there was a question about cruise control whch said that NO cruise control can hold a car from accelerating going down hill. Well I would beg to differ as my Passat annoys me sometimes as I pass cars going up hill when using cruise as most slow a bit on a hill. Then going down I get passed again as Cruise holds the car within 2 k of the set speed. This seems to be in contradiction of the so called expert.

What do other users find what happens.

My Toyota Landcruiser was bad for speeding up going downhill with Cruise enabled but the Passat is very much different. How it does it I dont know but it definitely does it regularly.

[Umai Naa!!]

Some cars are very good at maintaining the set speed, whilst others are not.

Back in the day when CC was just an electric motor pulling on the throttle cable, they were terrible at doing everything nicely.

[Idle]

I think they brake — certainly feels like it.

[kamold]

Adaptive cruise systems have control over the ABS control module as well as the engine ECU.
So they certainly don't just engine brake, they use the brakes hence how they can slow the car to a stop if the car in front does so.
Traditional cruise control systems can only alter throttle input so they tend to overspeed down hills pretty easily. They can engine brake up to a point and even drop cogs but they won't stay close to the set speed like an adaptive system can with access to the brakes.

I used to have traditional cruise and retrofitted the new ABS module and radar for adaptive cruise it certainly behaves very differently.
Haven't read the article as you haven't linked it but if it is stating adaptive cruise can't brake down a hill then its clearly misinformed.

[IsDon]

Even modern cruise controls without adaptive functions, (i.e. No radar) will still brake going downhill.

I have an MY13 Audi A6. No radar, no adaptive cruise. Initially it will kick down a gear to hold the speed and then it will brake.

No doubt about it.

The "journalist" is an idiot.

No surprises there.


Sent from my iPhone using Tapatalk

[kamold]

Most basic cruise control systems have no control of the brakes.
I'm not familiar with the A6 system but I would venture its not a basic system like most mainstream cars if it can also control the ABS module.

[Hillbilly]

Here is the articleAttachment 30142The question was about "Smart cruise " on the new i30 Hyundai whatever that is but may be similar to adaptive cruise I dont know. However on reading a review of the car seems it is a sort of Adaptive Cruise

[Kachingg]

Here is the articleAttachment 30142The question was about "Smart cruise " on the new i30 Hyundai whatever that is but may be similar to adaptive cruise I dont know. However on reading a review of the car seems it is a sort of Adaptive Cruise

Hmmm smart but not that smart...

My 7.5 brakes going downhill with cruise on i turn cruise off on 1 steep hill in particular and use paddles to drop to 3rd gear and use engine braking otherwise car will ride the brakes all the way to keep me at 60 i usually end up at 70ish at bottom but no wear on brakes

Sounds like the i30 is not as good with the cruise still good just not as good as ours

[IsDon]

Most basic cruise control systems have no control of the brakes.
I'm not familiar with the A6 system but I would venture its not a basic system like most mainstream cars if it can also control the ABS module.

I can assure you that the basic cruise control systems in high end cars most certainly control the speed of the car with the brakes. It is definitely not dependent on whether or not it has adaptive cruise. I first saw this in a 12 year old Mercedes, well before the advent of radar based adaptive cruise.

Now the article talks about an i30 and what it is calling "smart" cruise. Almost certainly this is Hyundai's version of adaptive cruise. If that's the case then it certainly would control the cars speed with the brakes. I admit that basic cruise controls in cheaper cars may not correct for over speed. My last car, an MY08 Subaru Liberty never did either. That's not what is being referred to in the article.

The author of the article has absolutely no idea how cruise control works. It doesn't use GPS mapping in any way shape or form to anticipate grades. To suggest such is nonsense. He is correct when he states that cruise controls are reactive. They react to variations in vehicle speed, both below AND ABOVE the set speed to either apply more throttle or to kick down gears and APPLY THE BRAKE to maintain the set speed. Not sure how he considers this a danger to following motorists. When the cruise applies the brakes it also switches on the brake lights. How is this any different to a diligent driver applying the brakes down a hill when the speed increases above the limit?

I stand by my earlier opinion. The "journalist" is an idiot.

[Sunny43.5]

When back in 1982 I bought a brand new Mazda 929 2door hardtop it had factory cruise fitted , its main problem was Mazda had introdued a new fuel system for the engine which would not allow engine braking as they allowed a small amount of fuel to be injected into the engine under deceleration . If you just took your foot off the accelerator in gear on a flat road the bugger would roll for miles before stopping . So when the cruise was engaged it would hold speed uphill to the top and then sort of release but because of the injection system it would go nearly 15kmh over the set speed as it was still getting fuel . I got pulled up by a motor bike policeman and I explained why it was doing 115 in a 100 zone on cruise , he hesitated for a few moments and then said that it was no excuse . After he left my wife said to me "you almost had him then he was thinking about it !! "