I was driving this morning and found myself wondering why the car doesn't keep a constant speed with the cruise control on while going downhill.

I can see how it might not work on a 6MT, but in an automatic, the transmission will automatically downshift if you're braking on the way down a hill and the brakes can obviously be automatically controlled since they are by VSA. Thus, why couldn't a combination of engine braking and brakes be used to automatically keep the speed steady when going downhill?

I figure that it's technically possible, but isn't done for some safety reason. Any thoughts?

 

its not good to ride ure brakes going downhills, theyll heat up.
n most of the hills here the car keeps the same speed i beleive, annoys me tho cuz i want that momentum to keep me going rather than push it away. then again florida hills are not even hills =/

 

Hills? What are those

 

VSA will only make small adjustments based on wheel speed. You put in another degree of complexity to the VSA by doing what distance control on auto-cruise systems do. Those are the systems that will auto brake for you in cruise control mode. I think JDM Accords have this now. I'm sure as soon as adaptive cruise systems get approved here, we'll see it, as for now, the compression of the engine is all that we get. BTW, cruise will downshift (in an auto) for you in a situation where you are going up hill, but not under braking.
We 6MT folks have to do that ourselves.

 

My father has adaptive cruise control in his new A8 So I think its already here :wink:

 

That was one and I think Volvo that I was unsure of. My wife's uncle tested it here on the VW Photon about 2 years back in AZ. So I knew there had to be a few manufacturers I was missing in my head.

Thanks!!!

 

You can get it as an option even in the relatively cheap IS350.

Like all other technologies it will trickle down soon enough.

 

really? didn't see that on the list. Man that IS is gonna be SAWEEET