Tom in Austin

After my first month enjoying the S550, I have determined these functions are not very helpful and often annoying for my driving style and conditions. I do like them on the freeway when using cruise but while driving around town I'd prefer to just switch them off.

I may not have the correct terminology, but here's what I've found: I don't like the vibrating steering wheel warning when I change lanes. Yes, if other cars are around me where it makes a difference to another driver, I should and do signal lane changes. However, in urban traffic there are lots of times when one sees an opening and makes a quick lane change. I've read there's a little motor in the steering wheel that spins a weight to produce the shaking feeling and I am tempted to take off the wheel, yank the thing out and toss it in the dumpster.

The second problem with 'lane departure' warnings is that I use the whole lane much of the time, dodging speed bumps, debris on the road, broken pavement, potholes and the generally dismal road surfaces where I drive. Our community never repaves streets, they just keep patching them again and again. In the few places they do repave, the new pavement is higher than the manhole covers, so you thump into each one as you drive along. In a theoretical perfect world with smooth, consistent road surfaces, it might make sense for the car to try to keep you constantly centered in the lane, but that is nowhere near the case where I drive. There are also bicycles and joggers to steer around, oncoming vehicles uncomfortably close to the center line, etc.

The final problem with 'departure' and 'assist' functions is the car does continually contend with the driver for control. It's a very subtle effect to be sure, but you can feel the steering doing something on it's own, and as slight as it is, it's distracting. Good straight-ahead tracking in a car is a beautiful thing where only the slightest inputs from the driver are needed to give him/her a feeling of complete control. Why would you want anything else happening?

I haven't looked at the owner's manual, but I'm hoping this stuff can just be shut off. If it comes on with cruise control, that would be fine, but under other driving conditions, I would just as soon it weren't there.

DaveW68

You can shut all of those systems down if you want.

Mitch Alsup

I, also, find them annoying.

Especially the <lack of> attention detection system. Driving down a long rather straight road, I see a pot hole in the road and maneuver the car to avoid the pot hole, the attention assist kicks in to say I must be falling asleep whereas the reality is exactly the opposite. The car saw a straight road and can't understand why I wanted to avoid a pothole !! Stupid systems, really.

I find it annoying that Distronic used the brakes to adjust speed downward when it could have let up on the gas a 1/4 mile earlier. Cruise control should NEVER use the brakes. Stability assist and crash avoidance can, but the wrong choices get made every friggen time I allow these things to get turned on.

Tom in Austin

I suppose it's still early days for these systems and they'll get better as time goes on. But they still need to comprehend real-world driving conditions ... as long as there are potholes and other obstacles out there, how would a system ever know if the driver is being unattentive or actively steering the car around things?

SW20S

It all can be turned off. I have lane departure and warning off but keep the self driving on for when I'm using Distronic.The buttons are all to the left of the steering wheel under the left air vent. You want the one with the two lines off (thats lane keep) and the steering wheel button on (thats distronic plus).

Dynamic cruise control has to use the brakes, otherwise its not dynamic. The whole point is that it will slow down and speed up to match the speed of traffic ahead, and it can't do that without the brakes.