BobES2019

Yesterday I was in heavy traffic (welcome to Southern California). I used the radar cruise control and it worked perfectly. The traffic speed varied between 45 and 0 mph. What I am wondering is what happens with the brake lights? The car was doing a great job in precisely slowing or stopping. Do the brake lights go on? If they do not, it seems a hazard for the car behind you to have a rear end collision. Does anybody know?

Thanks

dchar

The taillights go on whenever brakes are used to slow down the vehicle, whether using the radar cruise control or pre-collision.

BobES2019

Thanks dchar. That makes the radar cruise control a great feature for me. After a few hours in heavy traffic, it is easy to get distracted and rear end someone.

User 41924

You use cruise control the same way I do. I works great, except it's not very smooth. I suppose that's to be expected. It can't anticipate, or look very far ahead, which I consider to be KEY elements for smooth driving. I'm taking this car on a short road trip for the first time this weekend. I'll be able to use cruise for longer time in lighter traffic, so it has more time to react. I expect it to be much more smooth and less obtrusive. Pretty impressed with how well it works in general, though!

I've wondered about the brake lights just about every time the car slows on it's own. I read somewhere that the brakes lights function, but without seeing it for myself, I still wonder. I can't help watching the car behind me to see how that driver reacts. I've not seen any surprise or panic so far, so it must be true.

ES63

It is nice , however Lexus' is not nearly as smooth as others I used in other vehicles. very jerky,like a kid w a new drivers lisc in stop and go crawling. My prev car Genesis was always smooth as silk when crawling and following the car in front.

kalel2127

I use it about 90% of the time that I drive and agree that the ride isn't that smooth. My girlfriend has a 2019 Accord and that vehicle is smoother. I did notice that increasing the following distance to the max setting helps with a smoother ride. Also, not sure if it's just me but it feels smoother than when I first started to use it or maybe I just got used to the ride. The brakes don't seem to be bite as hard not sure if it's a cause of brake fade or something else.

mikemu30

Try max setting for distance.

whiteIS350

I have yet to use radar cruise in bumper to bumper traffic - only have used it in normal highway driving. Other than the steering assist ping-ponging, it’s been very smooth

User 41924

I have, and it absolutely improves! Unfortunately, it leaves such a huge gap between you and the car in front of you that some people seem COMPELLED to fill the space, so my car slows to increase the gap between me and the car that is now in front of me. Before long (usually before the gap is sufficient, someone else finds the need to fill the new gap, and the process repeats. I end up driving slower than everyone else, but the braking is much smoother. Unfortunately, I'm so irritated by people passing and changing lanes in front of me that I forget to notice. I've decided that it's better for my sanity to adjust to the the shorter distance and just deal with the alternating acceleration and braking. I did confirm that the brake light comes on when it applies the brakes! I could see the reflection from the light in the back window after dark!

I'm not complaining about the car!!! I think it works about as well as can reasonably be expected! We did take the ES on it's first (mini) road trip into the mountains this weekend, and the car performed flawlessly! I was very pleased! It is much smoother when using the dynamic cruise control with normal traffic.

I tend to let the car exceed the cruise setting to some extent when going downhill and use the momentum to carry up the next hill to save brakes, and improve mileage. This actually happens a lot in the mountains, but this car seems to "coast" really well and would be going a lot faster than expected pretty quickly. It uses the brakes a lot more than I would to maintain something close to the set speed because using a lower gear isn't (at all) effective for slowing. It's probably just an old school concern, but I worry about overheating the brakes. Not to mention wear. The car probably strikes a more effective balance that I can anyway, and adjust.

ES63

Its also still a bit anoying to me that i set it for say 78 mph and it goes to 77 and stays there. if I accelerate past the 79 then let it resume it will sometimes stay at what i set. reminds me of the the old Vacuum and cable controlled cruise i used to work on at the dealerships waaay back. no its not a big dea,,l just a bit annoying esp on the HUD never had a madern car 1 mph off consistantly.

LeeSoFL

I've noticed that "one mph off" too.

User 41924

I have a theory on that! I think it might be some sort of a rounding error. For example, If you’re going 74.7 when you set cruise, it rounds up to 75. The speedometer still says 74. Same going the other way. If you set it at 75.2, cruise rounds it off at 74, but the speedometer still says 75. I write this off as an issue we would never have seen with old (less accurate) analog speedometers. I also found (because this difference offends my OCD) that it sometime re syncs when I cancel it, coast for just a sec, then hit resume. I discovered this by accident, not by experimenting. I’m not THAT compulsive! I haven’t really been able to confirm the consistency of this discovery, but it’s worked more than once or twice. Plus, I can’t decide if this confirms or debunks my rounding error theory.

All i I know for sure is that I’ve spent WAY too much time thinking about it!

TrentYoung

Gee thanks.... now you will have me thinking about it!

mikemu30

1 mph irks you - this is known as OCD🤔 I've noticed mine spot on sometimes and off by 1 others. Never gave it a second thought.

LeeSoFL

Officer: "You know you were going 78 in a 70?"

Driver: "Actually Sir, I had set it for 79, but there's some quirk in the cruise control!"

Officer: License and registration please.