Adaptative cruise control

[bruceb58]

Brakes/gear change are used on both adaptive or regular cruise. The only difference between the two modes is that adaptive slows you down if there is a vehicle in front of you.

 

I wouldn't own a vehicle without adaptive cruise. When I drive for Los Angeles to Lake Tahoe(500 miles), its on the entire drive.

[Chuck FB]

5 hours ago, bruceb58 said:

Brakes/gear change are used on both adaptive or regular cruise. The only difference between the two modes is that adaptive slows you down if there is a vehicle in front of you.

 

I wouldn't own a vehicle without adaptive cruise. When I drive for Los Angeles to Lake Tahoe(500 miles), its on the entire drive.

Is that during the summer or winter time ?

[Ausslo]

On 9/18/2025 at 8:53 PM, Chuck FB said:

Oh ( makes sense too ) and I've not been driving at night all summer and to be honest past vehicles I could not see any portion of the brake light from the drivers seat while driving to know if they were working or not, that was always a test with a weighty object on the pedal to self check or by backing up to a building to see the reflection. In fact I will have to go out at night now and see if the Chev brake lights will show up at all in the mirror ... or are you forcing the rear camera to come on at highway speed to do this test ?

 

I saw a comment and not sure if it was on this forum from a while back about how fast the brakes were wearing on a truck and I have to wonder if it had something to do with this very issue, the truck applying the brakes on either the adaptive cruise ( which I thought was the only way they applied on their own in high range ... obviously mistaken ) or now realizing even on normal cruise. I could see though on very hilly roads as well as varying traffic, the brakes would be going on far too often for no good reason. 

I actually was curious if they lit up when the brakes were self applied (which made sense to me) so I had someone follow behind me while on the phone with them and asked if they came on when I felt the decell going down a hill and they confirmed that in fact they were lighting up.
It definitely increases wear, I use the cancel button to overcome it and still have half pad or more at 50k.
I rarely find a use for adaptive cruise as I find people cut so close to you that even on the min distance setting it over uses the brakes.

Edited September 20, 2025 by Ausslo

[bruceb58]

6 hours ago, Chuck FB said:

Is that during the summer or winter time ?

All seasons...I drive up monthly. It is not on when there is snow on the road.

 

These days, I rarely drive my GMC up there...I take my Rivian...also with adaptive cruise and FSD when I am on a road where it works.

Edited September 20, 2025 by bruceb58

[Chuck FB]

1 hour ago, Ausslo said:

I actually was curious if they lit up when the brakes were self applied (which made sense to me) so I had someone follow behind me while on the phone with them and asked if they came on when I felt the decell going down a hill and they confirmed that in fact they were lighting up.
It definitely increases wear, I use the cancel button to overcome it and still have half pad or more at 50k.
I rarely find a use for adaptive cruise as I find people cut so close to you that even on the min distance setting it over uses the brakes.

Ok that makes sense, I was thinking that maybe the way the Chev tailights are designed in how they wrap around a bit, that you could make out a little bit of light coming from them when the brakes were applied. If I think of it as I had mentioned before I will try and see if the rear camera will pick up more glow from brake lights coming on and if that works I can monitor the brake lights when descending a hill with the cruise on and see just how often the brakes are being applied although there is no way of knowing how hard the brakes are being applied.  

[Chuck FB]

6 minutes ago, bruceb58 said:

All seasons...I drive up monthly. It is not on when there is snow on the road.

You probably guessed what I was driving at, using cruise on ice as well as the adaptive cruise slamming on the brakes and your not ready for it. 

 

Last winter we had some fair spans of time with clear highways which is very unusual as so was the weather but normally the roads are unpredictable or put another way predictably horrible !. So no cruise being used at all typically unless its one of those perfect dry pavement winter road conditions. 

 

I've seen some videos of the wonderful road conditions going over the pass on I 80 during the winter and I can imagine the accidents are numerous, and a lot of vehicles with tires that are just asking to get into an accident as they came from the valley where its like summer time so who wants to wear out there tires doing that but then go to Tahoe to go skiing and and have summer slicks on ( or worn out tires ). 

[bruceb58]

9 minutes ago, Chuck FB said:

You probably guessed what I was driving at, using cruise on ice as well as the adaptive cruise slamming on the brakes and your not ready for it. 

 

Last winter we had some fair spans of time with clear highways which is very unusual as so was the weather but normally the roads are unpredictable or put another way predictably horrible !. So no cruise being used at all typically unless its one of those perfect dry pavement winter road conditions. 

 

I've seen some videos of the wonderful road conditions going over the pass on I 80 during the winter and I can imagine the accidents are numerous, and a lot of vehicles with tires that are just asking to get into an accident as they came from the valley where its like summer time so who wants to wear out there tires doing that but then go to Tahoe to go skiing and and have summer slicks on ( or worn out tires ). 

Yeah....common sense...which isn't very common.

 

I drive up 395 all the way which is on the Eastern Sierra side. If there are areas that become chains only, I drive up I5 instead.

 

I change my tires WAY earlier than most people do. Cheap insurance.

Edited September 20, 2025 by bruceb58

[Chuck FB]

2 hours ago, bruceb58 said:

Yeah....common sense...which isn't very common.

 

I drive up 395 all the way which is on the Eastern Sierra side. If there are areas that become chains only, I drive up I5 instead.

 

I change my tires WAY earlier than most people do. Cheap insurance.

I've never been over the I  80 pass in the few travels that have had me touching on California as a kid exploring the coastal redwoods in the north or as an adult and its years ago now in 2007 that I was last in California. I recognized the number 395 right away due to youtubers roaming around that highway and refreshing my memory. So in 2007 about the third week in July I had crossed over at Laughlin and then up to Death Valley and experienced a lovely 118f which for me was far hotter than I have personally ever been in ( the park office told me the temp it had been and said good thing you were not here last week as it hit 129f ) and then in the evening as it began to cool which is a relative term there !, I made my way west climbing out of the valley to 395 and by then the sun was setting so I didn't see too much of the Sierras at that point as I kept driving north to near Lee Vining. The next day went over Tioga Pass to Yosemte and saw some of the wonders of the park, the next day I hiked half dome ( that was interesting ... I am guessing you may have done that hike among others in the park ) and the next day hiked a bit more among the Sequoia tree groves and then headed south west to Paso Robles and out to the fantastic scenic highway 1 and then followed that up all the way until it joins up with the 101. Somewhere south of San Francisco I believe is where I stopped at a temporary weekend road side fruit stand and got ripped off by a young "valley girl" as after the fact I realized as I had driven on up highway 1 a ways and then tried the cherries and realized they were all rotten and had to throw them all away  .. uh good memories LOL. 

 

Thought you might get a laugh out of my California adventure !

 

I am only guessing that you would be on the minority side that would change your tires over to winters being that you live in southern California at the coast. There are a lot of people in Colorado at least from what I gather that never put winter tires, mind you some of them would be those that avoid going near the major passes if there are slick conditions because they know how horrible it is. 

[bruceb58]

Spent a lot of time in Yosemite but have no interest in ever doing Half Dome.

 

I have a house in South Lake Tahoe and we camp all along the Eastern Sierra. This is why I live in California...no other place like it.

Edited September 21, 2025 by bruceb58

[Chuck FB]

2 hours ago, bruceb58 said:

Spent a lot of time in Yosemite but have no interest in ever doing Half Dome.

 

I have a house in South Lake Tahoe and we camp all along the Eastern Sierra. This is why I live in California...no other place like it.

Of the US national parks I have been in ( which is only a handful or two of them ) I would say Yosemite ranks near the top of my favourites and like I said I did not have the chance to explore as much as I would have liked. The Half Dome hike, that was a whole different experience for me and I certainly was not in the type of shape I should have nor have ever remotely been in to be hiking that trail with authority. The cables were sure a mind game and I did stand on the diving board. You would have died laughing to watch me move the next morning as it probably looked like I was "carefully" moving with one end of a 10 foot length of tree stuffed up my butt and dragging behind me. I was in so so much pain but I pushed myself to keep moving and did the hike in the Mariposa Grove. I really like the natural landscapes of California I have experienced, what I have little to no interest in are the cement jungles.  

[bruceb58]

2 hours ago, Chuck FB said:

what I have little to no interest in are the cement jungles.  

Such a small percentage of California.

 

We just got back from a 2 week trip to the redwoods area in Humboldt county....amazing!

 

Yosemite is a very popular park(Means Crowds). There are many parts besides the valley floor that I go to and avoid the valley all together.

Edited September 21, 2025 by bruceb58

[Chuck FB]

7 hours ago, bruceb58 said:

Such a small percentage of California.

 

We just got back from a 2 week trip to the redwoods area in Humboldt county....amazing!

 

Yosemite is a very popular park(Means Crowds). There are many parts besides the valley floor that I go to and avoid the valley all together.

I would have barely scratched the surface in what I saw in the northern coastal redwoods relative to what would be out there to see. As a kid we drove through the Newton B Dury scenic parkway and someone had said just prior to be sure to take that side road as well as be on the lookout for the little sigh that says "Big Tree" which we did find and see. Walking through the forest with the ferns and moss on some trees looks like a photo in an old science book and the only thing missing is the dinosaurs. We did do the touristy thing as well as we toured the Trees of Mystery, that was back in around 1979 or so. As an adult I made a point to stop at the Big Tree and it wasn't looking so healthy by then, a huge branch had come crashing down and smashed the fence around the base of the tree and was still laying there not cleaned up, the parking lot had grass growing up through all the cracks as nothing was being kept up at that time in 2007

 

Funny you should say that about the crowds in Yosemite, that was the huge negative at the top of my list for that park at the time of year I was there, complete insanity within the valley during the day and stood in line hoping to get a campsite from a cancellation and I fortunately did. People streaming off of tour buses from groups from other parts of the world and hiking certain shorter trails so again the crowds. It was a dry summer and the water fall that comes over the cliff of the rock wall in the valley was completely dry as I imagine spring time would be the time to experience that. Then I think of Oprah and Gayles adventure with a pop up trailer in Yosemite they filmed years ago and the theme behind why they went to the park, I still shake my head over that whole embarrassing farce of a fiasco. 

[UWSkier]

On 9/20/2025 at 9:07 AM, bruceb58 said:

All seasons...I drive up monthly. It is not on when there is snow on the road.

 

These days, I rarely drive my GMC up there...I take my Rivian...also with adaptive cruise and FSD when I am on a road where it works.

In the Mercedes, I only ever use adaptive cruise. In my Silverado, I hate it and disable it (since I'm usually towing).  GM's implementation is crap compared to more refined brands.

[Homer1959]

On 9/18/2025 at 8:25 PM, Chuck FB said:

 I would be putting the trans into the manual mode to restrict how high a gear it would shift into and use that to shift down even more to set myself up for the proper speed for a longer down grade. 

 

 

Can you switch the transmission to L mode while driving at any speed? In L mode, do you have access to all 10 gears? Finally, if it works while moving, which gear will it be in—the one you're currently in or the last one you selected manually?Ive looked at the manual but its not clear for my limited frenchglish brain  

[Chuck FB]

6 hours ago, Homer1959 said:

Can you switch the transmission to L mode while driving at any speed? In L mode, do you have access to all 10 gears? Finally, if it works while moving, which gear will it be in—the one you're currently in or the last one you selected manually?Ive looked at the manual but its not clear for my limited frenchglish brain  

While I haven't had a reason to use it extensively yet so others may have some more feed back on all of its quirks, it appears that its somewhat ground speed dependent as to what gear it will go into when shifted into L, mostly it was at higher speeds when I shifted it and it dropped down a few gears all on its own but then in thinking about it I am not sure if its aggressiveness changes if its in tow/haul mode or regular mode as I haven't tried all scenarios myself come to think about it. But if your worried about it slamming into some low gear its not supposed to go in, it won't do that if the system is working correctly. Yes it has access to all 10 gears if you want it to be so its not restrictive if you don't want it to be but if you do want to "lock out" certain upper gears and for example that might be 10th and 9th, you select it to read 8 with the rocker switch and from then on ( within that key cycle of operation ) it won't shift above 8th gear. When coming to a down grade for example when lets say you were in D mode and you want engine braking, pull it into L and it will probably shift down some in that moment but to continue to shift down you keep tapping the - on the rocker and if its able to ground speed wise it will shift down one gear at a time as you tap the - . Now lets say your in manual mode and its showing 8th gear and you come to an up hill, the truck will continue to shift down as required on its own but the readout will keep showing 8. If for some reason you want to manually down shift going up a hill you certainly can do that if desired and using part throttle that would otherwise cause it to shift up in D mode, in L mode you can keep it down into a gear where the engine would rev higher and your lighter on the throttle. I could see that making sense on a longer hill climb in hot weather and wanting to allow the engine to not work so hard but have rpm and none of this issue with it wanting to shift up and then bog and shift back down. I don't have the experience like I say with this truck and towing to know how bad it is for constantly shifting when on hills, some vehicles are bad for that and all that does is cause more heat and stress as the trans keeps shifting back and forth and bogs the engine down and ground speed slows and then it shifts back down and round and round it goes. All that would be a learning curve for the trailer one is pulling as a light low air resistance trailer would be very different then a tall trailer pushing a lot of air or an all out heavy trailer in how a vehicle responds. 

 

Hopefully I answered that other question about what gear its actually in vs what the readout is showing you in the L mode, that the readout is only showing what it could potentially have shifted up to but not necessarily what actual gear its in at that moment. GM would have to have two readouts to give all the information, the readout it currently has which shows what gear it will allow itself to shift up into if its able to and a new readout that shows what gear its ACTUALLY IN in that moment in time. 

 

But now I know from what was said here that using any form of the cruise choices on these trucks means its more that likely applying the brakes on a down grade on top of its shifting the transmission down so that could get a person into real trouble using cruise down any length of hill by way over use of the brakes unknowingly to the driver who may assume its only the transmission having shifted down that is holding the truck back "so impressively". 

 

Right now even if your not hooked up to your trailer you can play some with your L mode and get a feel for it a bit but only by towing your trailer will you be able to determine what gear and ground speed your unit will be able to use to go on a down grade and for example not hardly touch the brakes. Its one thing on freeways with sweeping wide curves and no traffic and can go faster safely ( sort of ) but mountain grades on two lane narrow sharp curving highways one has to shift down and crawl and probably hold traffic back as otherwise the brakes would be toast long before one would get to the bottom if one didn't shift an automatic trans down manually and that is why exhaust brakes if effective enough are a game changer if doing a lot of that type of terrain pulling loads, the plus of the big three diesels on the market aside from their hp/torque advantages.