allisondbl

So I'm contemplating buying a Mercedes E350. I'll be getting it fully loaded with regard to safety technology, i.e., the driver assistance package including Disctronic plus with steering assist, lane keeping assist, surround cameras, adaptive highbeam assist, BLIS etc.

My specific query is with regard to the limits of the Disctronic i.e. adaptive cruise control system. My testing and my understanding shows that it is the most advanced on the market. It can be set to follow a car at a specific distance and once set, unlike other systems will actually stop when the car in front stops and then restart itself without driver intervention. Further, if the car in front stops for more than a given time, critical to me is that the car can be made to move again merely by tapping the resume button on the steering wheel.

The key for me is that when stuck in stop and go traffic at, for example, a tunnel, you no longer have to continually shift your foot from gas to brake to gas for an hour, but can instead hit resume and you move that foot or two and the car will stop itself when the car in front stops and resume moving when you hit resume and then stop when the car in front stops, etc. over and over.

If anybody knows anything contrary to what I'm saying absolutely contradict me pretty please! It is this ENDLESS REPETITION using resume that, to me, separates the Mercedes from every other car except, possibly, the Audi A6.

So: can anyone driving this level of Disctronic confirm that this works with no limit?? I raise this question having found out that the Subaru Legacy with its new eyesight technology for example, will not allow stop and go after five stops. I discovered this via a Subaru seller who was there when the Subaru test drive guy at Subaru headquarters took dealers over and over to a target to show how the automatic stop worked ... and went right through the target on the sixth time. Turned out that the Subaru is set up so that after five stops you have to turn the car off to reset it. This would render the Mercedes utterly useless for my purposes.

I'd also like to know whether, if one accidentally - or in panic - uses the brake and thus "turns off" the Disctronic, can it be set to resume with a flick of that resume button while stuck in that stop and go tunnel traffic even though one can't get the car up to the minimum normal speed to get the Disctronic to start?

Any and all help greatly appreciated with this thank you!

Alley

drsaab

Yes. Unlimited stops. Resume only needed if stopped for over 2 Seconds. Yes resume saves last speed until you turn car off even when you brake manually.

Flaws are only if your coming at full speed and a car is fully stopped in front of you. You need to brake yourself. Such as approaching a red light where there is a car stopped at the red light.

Also if following someone and they switch lanes at last second and now there is a car going much slower then the mb can't brake in time and will beep and shut off distronic.

ttoE550

I have Distronic plus on my 2010. Unless it has changed since, I believe everything you say regarding it is true. I will add that a touch of the accelerator will also restart from a full stop. I have used it many times in stop-go traffic, and have never experienced a limit. Yes, you can resume at low speeds provided that you are close enough to the car in front. I forget the exact distance, but it has never been an issue in for me in heavy traffic.

Just so you know, the system is described as distance based -choose how close you want to be in feet - but this would be nonsense in stop-go traffic. It is really time based, at least at low speeds. You can get nice and snug with the car in front, or back off a bit when appropriate. My only complaint is that the car is sometimes slow to recognize and accelerate if the car in front takes off quickly, as often happens when a jam clears a little.

GoBlando

The only other annoying thing is on a two lane road where you slow down for someone making a left turn, distronic will shut off after the car turns if you had to slow down too much.

Also, you definitely want it. I don't think I can ever go back.

rrayll

You really did your research and and your information is spot on. Whether Distronics Plus is the most advanced system is subject to debate, but it works great for me. I recently shopped and bought a 2011 E350. Fortunately among the choices available at the time was a car with the Drivers Assist Package that includes Distronic. Not realizing how great it is (and not on my must have options, ie P2, for the car) I was actually attracted to the included Blind Side Assist. But after driving the car for me Distronics Plus makes driving so much more relaxing and SAFE. Will never buy another car without a comparable system.
If you are shopping for a 2014, there may be some improvements to the system that I am not aware of, but I actually can't think of anything that can be substanially improved.
If you decide on a E350, good luck and I hope you will love it as much as I do mine.

ucla95

BMW's with the same feature ('Active Cruise with Stop & Go') don't turn off in this scenario.

michael61

+1

It's true.

I have a 2014 E 250 with all the safety options. Distronic+ is excellent.

In many types of stop and go traffic it's truly a self driving car.

thefisch

OP, I admire your research of the feature. There is nothing more disappointing than having something you paid extra for fall short of your expectations. Unfortunately, most test drives don't offer the time need to test the more complex features like distronic, attention assist, adaptive high beams, etc.

PeterUbers

I've been scared $h!tless a few times with distro... I was quickly approaching a car and it was not stopping my vehicle... Had to slam on the brakes... Just be careful. This was in the case where there was no car in front of me to pace and distro was activated

listerone

The Distronic Plus on my Bluetec may have been eclipsed by the current version but I found adaptive cruise and the start/stop feature to be interesting ideas but very much in need of refinement.The Distronic features failed during snowy/slushy/icy conditions (not really surprising) and in very cold,but clear,conditions as well (not pleased at all).I did,however,like the lane keeping and blind spot features and with my new "d",which lacks these capabilities,I find I need to pay more attention in certain situations.

Arrie

Distronic is one of the best features of this car but you need to remember it ONLY is a driver aid feature.

Distronic will not stop your car behind a stationary object no matter what it is. It will give you a warning like 2 s. Before hitting such object and applies I think 40% brake force 0.5 s. before the hit. This means you will hit if you don't take any action but with little less impact compare to not braking at all. If you hit the brake pedal at the warning the car will apply full braking power for you.

Distronic will also not prevent hitting someone in front of you if that someone slows down too quickly. I think I read somewhere that it has 0.5 g limit as slowing down so you need to step on the brake sometimes.

But, for the stop-and-go that seems to be most important for you Distronic is just PERFECT and works as you explain, re-activates from the stalk if you don't want to use your foot on the gas pedal.

You can also re-activate it when you come behind a stopped car after you are fully stopped but not before you are fully stopped.

I bought a 2011 E350 first that did not have this feature. After a year I went and swapped the car for a 2010 E550 to get the Distronic after using it in Germany in some rental cars. I will not buy another car without adaptive cruise control.

Long3494Qut

I enjoyed distronic and you are very spot on. After seeing my black E350 with distronic and 360 package, my older brother is about to swap his silver E350 to a diamond white with distronic and 360 package as well for the ease of traffic driving. It is a great function to have. Do keep in mind that the steering does a great job but can have a mind of it's own at times. Sharp curves it will NOT do...I know from experience ^_^

drsaab

Check out the 2015 Genesis distronic and Steering assistance video here. Quite cool. I think the braking is even better than what mb allows

http://m.digitalspy.com/tech/news/a5...oKehvwhvi9uN8K

screw991le

Nice read of all the above post, I will have to try mine in traffic.

allisondbl

You drsaab are a psychic STAR! I was re-reading this post SPECIFICALLY because I just found out that the Hyundai Genesis NOW seems to have EXACTLY the same type of ACC as Mercedes' Distronic at about $20k less and am thus going to check it out.

I saw the video you reference and was wowed so: ASSUMING the Genesis version of ACC is the same as Mercedes', given my preoccupation with technology for safety and ignoring the superficial wonders of a Mercedes - legion I admit - with money as an issue, if the Genesis fits me any TECH reason I should STILL go with an MB?

Thanks so much for all the input gals and guys REALLY appreciated!

Alley

thefisch

Glad to have the stuntman demo that feature instead of me. That was a cool video. Glad to see Hyundai include cutting edge features. More pressure for MB to innovate.

drsaab

The Genesis is new. For the same money you could get a 2014 Mb e350 CPO with distronic plus. (about 48k) . A new mb is alot more. The CPO mb now have unlimited miles warranty. I haven't driven the Genesis to compare. The mb gets better real world fuel economy. The Genesis also got the highest crash rating. So it's a tough call and a good time to be a consumer and a bad time to be mb since so many cars are now very close In comparison to there own and alot cheaper.

Look at the options on a 2015 Hyundai sonata ultimate pk. It has more than the mb. Active cruise , heated rear seats, etc etc and is $30k in real world selling price. Tech is getting cheap!

340z

Hi Alley,

One tech feature that 2014 and newer E's offer, but I didn't see on the Hyundai site (doesn't mean they don't have it) is BAS Plus Cross traffic assist. This function will alert you to frontal cross traffic/pedestrians/bikes. Where I drive (lots of city driving) this would be of value to me. Hyundai shows a rear cross traffic feature (not sure if MB has this or not), but doesn't list the the front capability.

Also found that the Insurance Institute for Highway Safety now is testing collision avoidance solutions. Both the E and the Hyundai got the top rating of '6 our of 6", when equipped with their respective system options.

http://www.iihs.org/iihs/ratings (select the make and model to see results).

On the cost side, one thing to consider is longer term resale. I suspect that the MB will do better than the Hyundai. This could make the total cost of ownership or lease payments closer than the price differential would suggest. Also MB gets pretty aggressive on E leases. The C's and E's are their volume cars. However, the Driver's Assistance package is not common equipment, so you may need to special order.

Either way, i think you are making a wise decision to invest in this type of technology, as people are so distracted these days.

As for the stop and go traffic with the Adaptive Cruise. I was recently in some nasty LA pre holiday weekend bumper to bumper stop and go traffic and used the Distrionic for the first time in that type of traffic. It functioned flawlessly and automatically for over 5 miles. It was a bit unnerving at first and my natural reaction to hit the brakes when cars started to slow in front of me finally caused me to hit the brakes, which disengaged the cruise.

PeterUbers

Distronic is also heavier on the brakes than I am... I like to ease onto the brakes when coming to a stop and distronic likes to slam on the brakes towards the end ... If used routinely I can see it burning through brakes pads faster than usual

petee1997

I just ordered a 15 E400 with distrionic plus, now called Intelligent Drive Package. There may be some improvements in this model. They are using the same software that is now in the new S class. There is now pre-safe for rear end collision and the stop and go for traffic will turn off if there are no hands on the steering for more than a few second. This is to prevent texting and such.

I have no base of comparison since my other cars only have blind spot and lane keeping assist.

ttoE550

I think I might even be harder on brakes than Distronic. I spent several years racing, and the traditional method of easing into the brakes is sometimes derogatorily referred to as chauffeur braking. Instead, the brakes are hit hard at the start (throwing stuff in the car forward) when the car has more momentum and is less likely to lock up. Then, as the car slows, the brakes are slowly released as the momentum declines and lock up becomes more likely. With this method, the weight of the car should smoothly shift from weight on the front to neutral weight so there is no sudden transfer of weight to the rear when coming to a full stop.

The tendency of people to ease into braking is the motivation behind the "panic braking" feature of many cars to apply brakes harder than the driver might intend. I had a Toyota that I regularly triggered panic braking because of my style. Drove me nuts. I do not notice it in my MB.

In any case, I have never had unusual brake pad wear in any car I've owned. I cannot remember changing pads on any car, and I keep most 6 to 7 years. If anything, it's taught me to keep stuff inside the car either minimal or secure!

allisondbl

And right there is the crux! AFTER you hit the brakes why couldn't you just reengage it as soon as car moved? As I understand it one can hit disctronic and set from ANY speed even 1 mph so why not reengage?

samkimg

+2
it works as advertised, and can be made more responsive according to the position of the E or S setting on the center console. Also, you can adjust the distance between you and the car ahead with the rotating switch on the end of the stalk. I lower the distance in very slow creeping traffic to minimize people rushing between my car and the car ahead, but generally in regular traffic, I keep it set to the maximum distance setting.

I've only had an issue once with late braking, but that was a driver suddenly coming into my lane ... but that why WE are still currently in control at all times, right?! Yes, I am ... because my car told me I was ...

Arrie

I don't think Distronic really is any harder on the brakes. It feels like it at the end of the braking sometimes.


As a mechanical fat to stop the car from a given speed takes exactly the same amount of braking energy no matter how you do it. Brake wear in general is caused by turning that kinetic energy of the moving car to heat energy and brake wear of the components. This all stays quite constant regardless of if you brake hard first or last on a stop.


Why it feels Distronic is so hard on the braking at the end of it is mostly because the driver is not pressing on the brake pedal. When you use your foot on the brake you don't feel the braking force the same way as when you don't press the pedal but I also do agree that Distronic leaves a bit too much braking to the end of the stop. I also am used to slow down a bit earlier and make a very soft stop at the end. It seems Distronic is programmed to brake just as people do in a big German city rush hour traffic.

340z

In this case, I could have, just by flicking the cruise lever toward me with a finger. i just chose not to. I'm generally not a cruise control driver. This was toward the end of a long trip from SF to LA. Traffic had been moving along, so I was using the cruise when the stop and go happened. Since it was engaged, I was curious to see how it worked in stop and go traffic, so I left it on for a few miles.

I would recommend that you take a long test drive in traffic in an E with Distronic (of the model year you are considering, since some of this functionality and the location of the cruise lever has changed over time) and a salesperson who is really familiar with its functionality and see if it meets your needs.