Hey guys,

Have you seen this video?

https://www.motor1.com/news/249370/mercedes-gle-coupe-rolls-over/

Do you think it's a design flaw?

 

I saw that video yesterday.

I don't know that I would call it a design flaw, but I AM surprised that it rolled over, given the circumstances. That roundabout was canted down, but I wouldn't think that it's enough to get the vehicle to roll, and he wasn't going all that fast.

Here's another link with more information on the video:

https://www.autoevolution.com/news/m...er-126417.html

According to both of these articles, ESP was off...

 

Nope. Any vehicle with a "high" center of gravity will be prone to rollovers. That's why MB includes ESP, to counteract the laws of physics. If ESP had been turned on, it would have intervened "before" the left front tire even left the ground. Apparently, this idiot didn't know about the feature, or intentionally turned it off. This is more evidence of why you need to KNOW YOUR VEHICLE. Have a thorough understanding of its features and how they work. Don't simply skim through the owner's manual. Read it thoroughly. Being that this was a rental, he obviously didn't feel the need to do this.

ESP (Electronic Stability Program)

ESP monitors driving stability and traction, i.e. power transmission between the tires and the road surface. If ESP detects that the vehicle is deviating from the direction desired by the driver, one or more wheels are braked to stabilize the vehicle. The engine output is also modified to keep the vehicle on the desired course within physical limits. ESP assists the driver when pulling away on wet or slippery roads. ESP can also stabilize the vehicle during braking. If ESP intervenes, the ESP warning lamp flashes in the instrument cluster.

Characteristics when ESP is deactivated -

If ESP is deactivated and one or more wheels start to spin, the ESP warning lamp in the instrument cluster flashes. In such situations, ESP will not stabilize the vehicle. If you deactivate ESP:

ESP no longer improves driving stability.
Engine torque is no longer limited and the drive wheels are able to spin.
Traction control is still activated.
Active Brake Assist is no longer available; nor is it activated if you brake firmly with assistance from ESP
PRE-SAFE is no longer available, nor is it activated if you brake firmly and ESP intervenes.
Active Brake Assist with cross-traffic function is no longer available; it is not activated even if you brake firmly with assistance from ESP
ESP still provides support when you brake firmly.

So the ESP warning lamp will flash when ESP is turned off and the wheels start to spin. It will also flash when it's turned on and ESP has intervened to prevent a rollover, tire spin, etc. I've witnessed the former. I turned ESP off just to see if the wheels would spin. They did! However, I would never do this while going around a traffic circle.

Think about this for a minute. ESP is so crucial, the ESP light illuminates when the feature is turned OFF. That's backwards from how features usually work. They want to make sure you know when it's off. According to the manual, the only time you should ever turn it off is: when using snow chains, in deep snow or on sand or gravel.


Traction Control is an integral element of ESP.

4ETS (Electronic Traction System)

4ETS traction control is part of ESP. Traction control brakes the drive wheels individually if they spin. This enables you to pull away and accelerate on slippery surfaces, for example if the road surface is slippery on one side. In addition, more drive torque is transferred to the wheel or wheels with traction. Traction control remains active, even if you deactivate ESP. E.g. If your left front tire and right rear tire are sitting on ice, torque will be sent to the right front and left rear tires.

 

Here's an interesting link. Those massive, sticky tires on the Coupe make ESP even more necessary. So, do the performance tires make the Coupe more likely to roll over than the all-weather tires? Not likely. They just make the ESP work a little harder. This should be a word of caution to anyone considering buying any SUV. If it doesn't have some type of electronic feature to prevent rollovers, DON'T BUY IT.

https://www.consumerreports.org/cro/...-101/index.htm

"Good grip, but not too much. In any case, tire grip plays a paradoxical role in rollovers. Ideally, your vehicle would stay on course, gripping the road with all four wheels on the ground, no matter what. But too much tire grip can allow excessive sideways forces to build up until the vehicle flips over. Before that happens, you want the vehicle to gradually and predictably lose some lateral grip. Sliding is better than tipping over, but that too can put the vehicle at risk of hitting something during the slide, and then rolling anyway."

 

I was at the AMG Academy at COTA June 21st. We did the skid pad with and without ESP. You couldn't get the car to spin on the wet pad with ESP but as soon as you turned off ESP, you were spinning. From my experience, it would be hard to wreck the car with ESP active. Just my two cents.

 

Precisely!