Just back from a summer road trip of some 2,800 miles, 54.5 hours of driving and an average 30.5 miles/gallon fuel usage.

Route: Sacramento south to Bakersfield, up and over the Tehachapi pass for a night in Barstow (in the running for arm pit of California). On to Flagstaff, AZ and a multi-day stay in Chama, NM. From Chama north to Boulder, CO, and across Interstate 80 back home in Sacramento. Elevations from 200' to 10,300' above sea level, and a lot of driving in the mile-high elevations.

Our rear wheel drive GLC300 performed flawlessly, and we harmed way too many insects in 6 states-fortunately they all washed off. There may have been instances of ~ 100 Mi/Hr in some of the high desert driving we encountered, though I cannot exactly remember.

The quiet ride continues to impress me.
4-Corners - 1/4 way through the insect destruction derby - where the states of Utah, Arizona, New Mexico and Colorado adjoin at 90 degrees to each other.<br/>

Google Maps Places

 

Glad to hear you had a good trip sounds like you had a great time.

My wife and I just finished a 5K+ mile road trip in our 2017 GLC300 4 Matic and I put together some thoughts one day while my wife was driving. The trip started in Arizona 2 lane roads until Lordsburg NM then I-10 to Midland TX. From Midland we took US84 all the way to Alabama then down to Florida. Eastbound trip ended in Ft. Lauderdale FL. Local driving for a few days then the westbound trip started. We did not intend to drive interstate system all the way home but that's how it turned out. North to Georgia, southeast to Alabama again picking up I-10 in Mobile, visited family in Houston then on home. Must have killed a couple hundred thousand bugs or at least it seemed so.

1. Navi - I'm beginning to think it is way behind my phone in capability or even my $300 Garmin unit for that matter. It is very difficult to do an online search for a destination, I don't know what the car uses but I tried to look up an address online for a hotel that has been open for more than 2 years and the system couldn't find it. Not only couldn't it find the hotel, but the system said the address didn't exist, not just the number, the street. Since this street is in TX and is the frontage road for I-10, it's been there since the interstate was completed lots of years ago. POI searches are essentially useless, nothing I tried to find existed. Mercedes apps searches are useless unless you have very good cell service, the system times out fairly quickly when trying to load the apps, so just initiating a search is a PITA.

2. Sirus/XM - Used Sirius almost exclusively during the trip. We lost signal one day in southern GA on the I-75 south of Atlanta for no apparent reason. Sat radio stayed unavailable for the rest of the drive until we shutdown at our destination. Sat radio came back later when we restarted car. Might be hardware, might be software the trouble did not re-occur. Another issue we had for the entire trip, was the volume would change randomly on all channels. Typically it got louder for a few seconds each time then return to set value.

3. Distronic - Love the concept, worked as intended most of the time. Couple of thoughts; it decelerates for traffic ahead pretty abruptly which isn't bad once you get used to it, then would maintain the set distance and when the way is clear, it would start accelerating back to preset speed very slowly as if it is thinking "should I or shouldn't I? Oh what the heck I'll accelerate now". Also, and I understand the reason, the radar sensors are somewhat sensitive to rain. The system would display a message that the radar sensors were unavailable when we drove through a few moderate rainstorms.

4. Mileage - Seemed to be pretty good for the size vehicle and engine (turbocharged 4 cylinder). Overall average was 27MPG, with a high of 33MPG in the SE US (Florida) and the worst 22MPG in TX hill country fighting a headwind and cruising 80ish MPH (that's the speed limit). Most of the time we were seeing 25-27 on the "Since Start" display which is an average. The figures I have above were calculated manually with fuel used and miles driven.

5. Tires - The Pirelli Scorpion MOE tires were pretty quiet for the entire trip depending on road surface. Pressure was maintained @ 36 rear and 34 front. Ride was comfortable. I know we have run flats, but I purchased a "slime" plus pump kit before departure because I knew we would be driving through some pretty desolate areas and wanted the option of going more than 50 miles @ 50 MPH. Luckily we didn't need the kit and it will remain below the floor in the luggage area for potential future use.

6. HUD - I had a problem with the HUD one day and I will be bringing this to the attention of the service department. The right side of the HUD seemed to have a dark blob (that's the best way I can describe it) growing from the right edge toward the center. The display at the time had Distronic speed display and speed limit on the right. The blob grew to block about half of the circular speed display so speed limit was gone completely. I turned HUD off and back on a number of times and the entire display finally returned, but the speed limit graphic is still very sawtooth on the edges and is not as clear as the rest.

7. Windshield wipers - I've seen this issue in other threads. The wipers "judder" after being used for 15-20 minutes. By judder I mean you can see them skip across the windshield. My temporary solution was to use one quick squirt of windshield washer fluid, that solved the issue for 20 minutes or so.

Overall - This is a good 2 person road vehicle. We had 4 people in it for the first half of the trip and although seating was OK, baggage carrying capability leaves a bit to be desired. With 2 carry-on size bags, 2 medium dufflebags, 1 computer backpack and 1 small cooler (only holds about 8 12 ounce water bottles) we maxed out the luggage area.
Notwithstanding some of my comments above, we do like the car. Would I recommend it to a friend now that we've taken a trip in it. I truly don't know. It would depend on what the friend was looking for. The electronic systems on the car could be improved, the mechanical seem really good.

OH, one other thing. I seem to gravitate more to the big knob under the touch controller more than the touch controller when using the Command system. I don't know why.
ere's a synopsis of our trip.

 

Thanks for sharing. Nice insights for those of us who haven't gotten our GLC's yet. Reads like this kind of gives us a heads up for things to be aware of, but I read without expecting to necessarily have the same experiences. Good or bad!

 

just finished around 600 miles, first long trip. want to echo some of the staments and add some as well:

COMAND: Agreed any current smartphone NAV or even the 3 year old garmin i have seems to be better. biggest issue is that the system barely gives you any notice on next steps - she usually tells you to take a left not long before you need to and then you have to figure out how to cut across a lane or two. and the split screen, right side screen doesn't clear things up much. worst part is my google maps will update automatically with new features and it was free. i did find that voice command searches worked pretty well. also had the dynamic route on and it rerouted basically whenever it got a word of any little nav traffic - for a few minute delay i would rather just stay on the highway. also wish on the screen somewhere would tell you when next turn is - even if its 50 miles away. i know you can use screen in front of driver for that but i like to keep that on radio.

Distronic - agreed, it accelerates lazily and jams on the brakes more than i would like. definitely a nice feature as it makes highway driving much easier. one time though someone cut in front of me and it beeped for me to break. seems like i would have needed the systems help most then and it bailed on me.

Fuel economy - since start which was mostly highway averaged just over 30 MPG - really good. did not verify myself. (Question - when does since start reset? some days i start driving in the AM and it continues from the day before)

Ride overall was quiet - even with the RFT's. If this thing had normal tires and a spare like it should the ride would be unbelievable. definitely a comfortable vehicle to cruise in. even when i hit a big bump i could hear it from the tires but i didn't feel it in the seat - great job ny the suspension. (Did notice a few times the odd wheel shake at big bumps - hope they come up with a fix soon). my tires are higher pressue in back than front (following one of the placards and not the other), wonder if keeping them at the lower pressure would make it even nicer.

back seat space is good. 110V outlet in back is nice. USB in center console doesn't seem to give much juice.

online feature seems OK,. buit are so painfully slow they are basically useless.

wipers - mine were kind of noisy all along then all of a sudden they got MUCH worse. not sure if worth mentioning to the dealer until i hear of a real fix.

Agreed storage space is limited. its a shame the back is so small. definitely 2 people and luggage is comfortable - as you can always pop down a seat or two if you pick something up on the way.


overall - very happy. the vehicle is comfortable and quiet cruiser. highly recommended. onlyreal downside is the boot space and while the COMAND is not even near best in class once you learn it is has a lot of features and gets you where you need to go

 

We just finished a 3,000 mile road trip running in our new GLC 300 Coupe. Traveled from Phoenix-Santa Fe, NM-Amarillo, TX-Arlington, TX-Fredericksburg, TX- Marfa, TX (!)-Phoenix.

Car had 800 miles at start and ended with 3,750 miles on the odo. Drove in a heavy thunderstorm in NM, and experienced the dreaded wiper shudder, which shots from the windshield cleaner fixes temporarily. Drove in heat, high humidity in TX Hill Country and dry desert heat near Marfa, TX (saw the famous Marfa Lights--they ARE real!). Back across dry, hot southern NM and AZ to Phoenix. All systems worked flawlessly! My only beef is that the cruise control stalk is not visible to the driver, hidden behind the steering wheel spoke. You have to fish around for it and remember which way to move it--not too good that.

MPG = 28+, MPH = 80+ in TX, and 75+ in NM and AZ. Minimal amount of oil used-1/4" on dipstick. Great cruiser this Mercedes, coming from 16 years of BMWs (last one a 2015 X3). The Mercedes Turbo 4 is not as smooth as the BMW Turbo 4, but feels like more torque is there at all rpms (it is). This car feels more solid and secure than my Bimmers and is certainly more elegant inside. It is a sweet ride that we will enjoy for a long time for sure.

 

I had a similar problem, only once, with my HUD, and it was due to the sun shining directly down into the HUD aperture on the dash during a straight stretch of highway driving. As the sun moved slightly, the black spot shifted from the left side of the display to the right. My guess is that the HUD uses an LCD display. From chemistry courses I've taken, I know that liquid crystals have what's called a "clearing point": a temperature above which they no longer function as liquid crystals. This would serve to turn the display black. Once the road turned and the sun no longer shone directly down into the mechanism, the HUD display returned to normal.

If you're still having problems with it, I'd take it to the dealer to make sure that the display isn't damaged. Good luck!

 

Thanks for the informaiton, I never thought about potentially being and LCD display. I think though that mine may have been damaged slightly. Although the entire display is now working, the speed limit "sign" on the right has ragged/pixelated edges not visible anywhere else in the display.

 

It's insect season: I'll never forget the number of grasshoppers that would cover the front of the family car out in the SW!


More pictures!

 

Since several of you have cranked up some serious miles travelling around the country, I was wondering how accurate/useful the Speed Limit sign display is? I'm not getting the HUD, but it will display in the screen above the steering wheel.

Also, is it sort of a picture of the sign or a preloaded sign that the car thinks it saw?

I'm always asking my wife "is the speed limit still 65 (or 70) or has it changed?" So I'm looking forward to this feature...if it works!

 

I did not try the display above the steering wheel. But on the Nav. screen it was amazingly accurate driving around Europe, it immediately changed every time when passing a speed limit sign.

A small speed limit sign appeared in the upper left of the Nav. screen. The signed on the screen looked just like the real sign.

How does it do that? Is it using some type of sign recognition software, similar to facial recognition software?

 

So the speed limit sign shows up in the actual Nav screen as well as the HUD display? I guess I'll find out soon enough! I was just expecting it to display on the dash.

Good to hear about the accuracy you experienced in Europe.

 

I may be mistaken but I believe the US version is tied to the NAV database, meaning the car doesn't actually "see" limit signs. Might be different is Europe though.

In our 5K plus trip this summer we did see a few instances where the actual limit was different than that displayed, usually around cities, on roads that had construction zones, etc. System did not err on the side of caution either, a couple of times it showed freeway limit for miles after limit reduced entering a city.

 

That's interesting. I, too, assumed when I first saw that feature that it was somehow fed that info through the Nav system. I think I then decided it would be wayyy to cumbersome for that to be maintained, even by a "Traffic database", and I think I saw something mention that it would pick up slower work zones, etc. which made me think it was a real time version of speed limits.

Your last comment about it not showing a lower speed limit as you enter a city could be bad news if you didn't notice it yourself.

Anybody know how this really works? And I apologize.....not trying to highjack this thread.
It could be an important part of Summer Road Trips.

 

Your experience in the US is different than what I experienced in Europe, maybe the Nav does function differently here.

Here is a link to an array of European speed limit signs: http://www.istockphoto.com/photos/ro...eed-limit-sign

As you can see there is a wide array of speed limit signs. What I found amazing was the Nav system adjusted the displayed speed limit for every type of sign shown at this link. Even the overhead LED Reader Boards and temporary construction zone signs. This made me wonder if some type of real time recognition software was causing the displayed speed limit to adjust so quickly, because a data base would not keep up with the LED Reader Board's dynamic changes according to traffic conditions, would it?

But I am just guessing how the system determined the current speed limit. Does anyone on this board know how it actually works?

To answer your other question, I don't have HUD on my car, so I can't speak to what is shows. But it makes sense HUD would show the speed limit. But, yes, the Nav screen does show the current speed limit, when the Nav screen is on the command display.

If the speed limit can be displayed on the dash screen above the steering wheel, as Vaboy mentioned, that would be more beneficial because the command screen changes when using any of the other command functions (radio, CD, etc). It can be changed back to nav, but the dash screen would most likely not be change as often.

 

I should also mention that the nav system has a real time road conditions function. My understanding is this function can be used to dynamically change the route according to road conditions. It would make sense that such a function could also be used to dynamically learn the speed limit (at least that makes sense to me :-) ). I am guessing how the road condition function works because the Nav system prominently displayed that the function was not enabled for Europe when attempting to use it over there.

 

i believe that is part of the XM Nav Traffic, which is free for 5 years, and after that will go away if you dont pay for it.

i likewise turned it on but i must say i am not sure whether i liked it or not. last trip i took it rerouted me off the highway a bunch of times - i would love if it gave me the option and told me how much time i would save like my handheld Garmin does. i cant confirm but i got the feeling that it rerouted me to save me minutes from highway traffic - but to save say 10 minutes or less i would prefer to stay on the highway as the side roads will typically take linger than expected.

 

Looks like the Speed Limit Assist that can display in the instrument cluster is included in Pkg. 3 only for MY17. It says it uses info available from the Nav system to display in front of you. Sorry I brought it up if that's the only way to see it (other than the HUD) which I didn't get anyway.

For MY18, it's included in the Premium Driver Assistance Pkg (Code 997 for $3,150).

 

I got the P3 Pkg (P3 includes driver assist), so I'll have to check out how to display the posted speed limit on the Dash screen when my car arrives. The car is currently going around in circles waiting its turn to enter the Panama canal zone.

 

Hope your ships number comes up soon, tedjane.

Also hope we see some more road trip write-ups. It's really helpful to read how others are using the technology and other features of their GLC's.

I'm going to MD in early August for a wedding, not exactly a big "road trip", but it'll be a chance to check out all the features in my new ride!

 

I just finished a road trip from SW Florida to Boston. 1500 miles. Averaged 30.1 mpg. Much more comfortable than the GLK. I never got better than 24 MPG on either of my GLKs. Two big dogs and suitcases in back. The rear hatch is higher from the ground than the GLK. The dogs had to be lifted in. We used iPhones and iPad for navigation. The A/C is strong, had to lower the fan speed from 4 many times. Heavy rains one afternoon, got the wiper shudder which is annoying. Visibility out of the rear quarter is partially blocked by the passenger headrest. 4600 miles on the car now. I didn't see many on the road, I've seen more GLCs since I arrived in Boston than on the road. I love the car.