Cruise control braking
#11
You do realize that the purpose of cruise control is to control/maintain a single, driver determined speed, right? Well, gravity and going downhill tends to cause the vehicle to speed up, above that set speed. Brakes are the only way to fix that issue. If you're not on cruise control you can see the hill coming and lift in advance to maintain speed. I'm sure some day that sort of "smart car" will exist, but until then you're gonna have to either turn the CC off or raise the speed a bit on the hill to allow the car to coast and the computer not to see a speed that is out of the allowable range.
Not sure I understand the concept of raising the cruise speed when going downhill, either .. I mean, if you want your max speed to be 80, raising it to 90 going downhill is ... going to make you go 90.
The best bet is to do what the one other member said - flick your cruise control off when going downhill, then pull to resume at the bottom.
#12
AudiWorld Super User
In the real world, these things are still comparative aero bricks...
It takes a very slight bump up on the cruise control on most downgrades at highway to get downhill momentum offset by aero drag. It's just another way/style to use the vehicle controls if desired. Relative to "older" vehicles, the 8 speed tranny means there is little engine drag, and even less if it has a "sailing function" (the Hybrid), so those are no longer particularly effective to slow the vehicle in som everyday downhill scenarios. Nor even the first gear (7th) stepdown or two as another potential highway technique; TDI's w/ the higher baseline diesel compression may have a bit more drivetrain effect though when off throttle.
Back to OP's question, from a safety perspective, I think the manufacturer would have to be out of their collective engineering minds to let speed go up meaningfully without volitional control by driver. Similarly, why you don't tend to find this stuff as a hack or mod somewhere in the electronics w/ VAG COM. The whole purpose of the adaptive overlay on old fashioned cruise is to deal w/ changing road and traffic conditions. Letting it go up unnecessarily by remote control invites blaming the statistically occasional accident on "the car" or the speeding ticket on the same.
When you actually "want it," it may also save an occasional ticket. Here in CA traversing the Sierra's a good number of times per year, I have become familiar w/ true downhill cruise effects (including areas steep and sustained enough to have runaway truck gravel offramps), Hybrid sailing function and the like. And no surprise that on I-80 through the Sierra's you predictably find more CHP hiding in the weeds, on overpasses (literally) and around ramps with their now laser and sometimes still radar either where the road opens up or along the downhill stretches.
Back to OP's question, from a safety perspective, I think the manufacturer would have to be out of their collective engineering minds to let speed go up meaningfully without volitional control by driver. Similarly, why you don't tend to find this stuff as a hack or mod somewhere in the electronics w/ VAG COM. The whole purpose of the adaptive overlay on old fashioned cruise is to deal w/ changing road and traffic conditions. Letting it go up unnecessarily by remote control invites blaming the statistically occasional accident on "the car" or the speeding ticket on the same.
When you actually "want it," it may also save an occasional ticket. Here in CA traversing the Sierra's a good number of times per year, I have become familiar w/ true downhill cruise effects (including areas steep and sustained enough to have runaway truck gravel offramps), Hybrid sailing function and the like. And no surprise that on I-80 through the Sierra's you predictably find more CHP hiding in the weeds, on overpasses (literally) and around ramps with their now laser and sometimes still radar either where the road opens up or along the downhill stretches.
Last edited by MP4.2+6.0; 05-25-2014 at 01:00 PM.
#14
AudiWorld Member
My SQ5 is different. I know about the braking. The A4 loaner did it, as does my wife's Toyota. The SQ5 however, works like no other cruise-control I've had before. I can set the speed to whatever I want while it is disengaged. Then, I can engage it with resume and it will match that speed quite gradually. I have dropped it 30 MPH quickly and did not notice any braking. If it did, it was very casual, unlike the Toyota and the A4.
An example would be cruising at 80 and about to come into a town that is posted 50. I can hold down the decel and it shows 79, 75, 70, 65, 60, 55, and I let off at 50. It slows down so gradually that I really don't think it uses the brakes. Same going down hill. BTW, I do NOT have the adaptive CC.
An example would be cruising at 80 and about to come into a town that is posted 50. I can hold down the decel and it shows 79, 75, 70, 65, 60, 55, and I let off at 50. It slows down so gradually that I really don't think it uses the brakes. Same going down hill. BTW, I do NOT have the adaptive CC.
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