Hi, I've bought my 2020 RX 450hL recently. I was surprised that the cruise control does not have speed limiter function. It is a very useful function to keep the speed limits easily. Most of other manufacturers have this function today parralel with other basic cruise control functions. Why does Lexus not have this? It is annoying. Could I hope perhaps, a software upgrade will solve this in the future?

 

The North America market does not offer such a feature, as most would go mad here beyond what they already are with it engaged.

Randy B

 

Probably because the demand is not here in NA. I know most cars in Europe have it.

 

I got a 2019 RX 350 and mine is quiet aggressive at keeping at my cruise set speed. I live in the highlands and feel the car dropping gears and slowing down to keep my cruise at the speed I set. The only way I can describe it is like the jake break on my GMC 2500 Denali HD when I turn it on. I would prefer if it didn't try and slow down while going down the mountain sides, cause even like 10 over and trys to slow down.

It's very frustrating, especially in the highlands because there are times; its almost like the software errors and the car gets stuck at like 4000/4500 RPM and its just reving away when I hit a flat straight after rolling down the mountian and I have to turn the curse off to reset and stop the over rev.

Maybe its because yours is a hybrid and it tries to save fuel and you don't notice it as much, or it is not as aggressive?

 

Sorry, but what is a speed limiter function?

 

It limits the maximum speed of the car. For example, some commercial semi trunks are limited to 65 mph and they can't go above that.

Different than a cruise control that you set yourself.

Some cars have intelligent senors that know what street you're on and sets the car's maximum speed to a number and will alert you if the car goes over that limit.

 

Yes, you're right, the question must be clarified: there are basicly three different features, which use the same name "speed limiter":
1) absolute speed limit set by factory: ie. 250km/h in Europe.
2) adaptive speed limit (called also intelligent speed assistance): the car sets the actual speed limit itself, based on built-in GPS map data, and its sign recognition camera.
3) manual speed limit: this works like the contrast of manual cruise control (called tempomat in EU): you can set a maximal speed manuallly by the tempomat switch, and the car won't go faster as this limit, undependently, how much you press the accelerator. It is a very useful way, to keep the speed limit on every road, while you use the accelarator on a normal way.
I miss this 3rd function. I'am on the European market. As you wrote, it seems to be not a demand in NA, only in EU. And RX is basicly developed for NA, and not EU. :-(

 

Thanks, that clears it up for me. I never knew that existed.

 

It's not just a hybrid thing, my FSport sometimes gets hanged up at too low of a gear on cruise after it climbs a slight incline. I can be cruising at 1800 RPM then a slight hill causes downshift and it's at 2800 RPM, the road will level out and instead of up-shifting it will hog that lower gear for like a minute or until another load change and it might reset afterwards. It doesn't always happen but is frequent enough to notice.