I'm sure there are other threads on this issue, but my 2 month ownership experience just hit a brick wall ... due to a nail!

Yes, there are some design things which niggle us, but the 2,600 miles since taking ownership have been fun ... and the car gets lots of compliments, especially about the color. Heading out to dinner the other night we got a tire pressure warning. Because we were only 10 miles from home I turned around and put it back in the garage. The next morning I tried to fix the issue - a pesky nail in the outer most circumferential groove of the rear tire tread - and the ownership euphoria hit rock bottom. A local, reputable tire dealer wouldn't touch it ... his equipment doesn't work on low profile tires (the rears are 285/35 ZR 21 ContiSportContact). So I called roadside assistance, who put me in touch with the nearest MB dealership. I offered to drive the car there (50 miles away), on the basis that I have run-flats, but the dealership pointed out these are not run-flats! The dealer we purchased it from, near our primary residence over 300 miles away, assured me they were run-flats ... but who gets down to find whether they have an MO or MOE designation on the side of the tire? There is nothing in the trunk ... no spare, no jack, no wrench, not even a can of goop ... this is weight saving gone crazy! I started the process before 9:00 am, the recovery truck finally arrived at 4:00 pm ... it's a good job we weren't stuck on the side of the road on a dark, wet, cold night. I'm currently waiting to hear whether the dealership can repair it, or whether it needs a new tire - we do have the wheel and tire warranty - it will take a couple of days for them to locate a new tire. Then I need arrange a lift for the 50 miles to pick it up!

When I ordered it I knew the vehicle didn't come with a spare, it was one of those trade offs I accepted, confident that the run-flats would be OK to get me home for 95% of my trips. But the fact that I don't even have that fall-back, together with a terrible response time from roadside assistance (they sent the truck to an address 60 miles away!), leaves me concerned about the safety and security of my family whenever we're out in this vehicle.

 

Not sure where you are located, but in the US the GLC43 with 21's certainly comes with a can of "goop". It should be located in the back, on the driver's side, behind a panel...check owner's manual for exact location. If you don't have or can't find, I'd immediately address this with MB or your dealer. I dread getting a flat with no spare, but will take the chance every time versus run-flat tires...hate them. Good luck!

 

Goop also standard in UK.

 

sorry to hear that! if the nail in the side wall, basically you can't patch it or plug it. lucky you only had 2600 miles on them, otherwise you need to replace both tires!
20 inch below tires are Extended Mobility tires (= run flat), 21 inch and up MB will included a Tirefit kit should somewhere in the trunk.

I alway had AAA plus, just in case that happen on the road. is only $100 a year, they allow to tow up to 100 miles 4X a year, plus you get discount on other things. so it may paid off itself.

 

No can of goop ... hunted everywhere. Getting conflicting stories from the dealership(s) and MB Concierge (guess I shouldn't be surprised at that!) ... when you select the 21 inch wheels, the build also adds TireFit, no-one can tell me what that is. A google search comes up with the can of goop, although the arm wavers say it's just a way to configure the central info display (BS meter on full scale here). They also add that the goop is a problem, and it's been eliminated from the build cycle, something about once used it needs to be thoroughly cleaned out when they remove the tire for a permanent repair.

My nail was in the tread portion of the tire, so they have been able to repair it. That being said, I'm rattled by the whole incident ... we're only one nail away from being stranded on a highway at night/a bad part of town/somewhere that has no cell coverage. This situation is unacceptable and I'm not getting any traction with my requests to MB for a way to feel more confident about driving the vehicle on a long trip. Their only response is to call roadside assistance ... been there, done that and it was a total bust.

I have come up with one possible solution, but cannot find anyone to substantiate it. Continental also has a version of the ContiSportContact tire which features ContiSeal. The tires come in the same sizes as the tires on my GLC and (per Continental) it makes no difference to the tire dynamics. Looks like the tire is OEM equipment on several higher end autos (Rolls Royce, etc) and the extra cost is only about $100 per vehicle. (MB must have spent that, and more, to get my vehicle recovered!) If I read the brochure ware this seems to be just the answer to my dilemma, it's only good for holes up to 5mm and doesn't work for sidewall issues, but it would enable me to continue driving with a pesky nail in the tire. Does anyone have any views or experience with tires using the ContiSeal technology?

 

You'll probably have to call MB Customer Assistance Center...800-367-6372, if you are getting the run around. TIREFIT is THE name of the system that comprises the sealant and electric pump, so not sure where the confusion is with dealer and/or MB Concierge. Not to mention, it's in the owner's manual, as well. Did you buy your vehicle off the lot? If so, perhaps the dealer switched out the 21's from another 43 (person didn't want 21's) and that's why TIREFIT is missing...just a thought. Either way, MB should resolve immediately.

Good that the nail puncture could be fixed and you don't have to buy new tires. These Conti's will need to be replaced soon enough as treadwear is pretty bad. Again, push MB to send you TIREFIT immediately or better yet, have them contact a dealer close to you and verify they have one to give you now.

I don't know anything about the ContiSeal, so can't help ya there...sorry. There are inexpensive tire repair kits (plugs) on Amazon that might be helpful and would have helped you in your situation, but then you'll need the jack, etc...ask MB for that, as well. Your vehicle should have come with one or the other. Good luck!

 

My 2018 GLC 43 has the tire fit kit (I have the 21" Continental tires) although I had to look in the manual to find out where MB stores it I do not think I would have found it without looking in the manual since it is not obvious.

 

Back on the road again, with a repaired tire. Plus the TireFit kit has been found!

No, it wasn't a spec vehicle on the lot, we did a custom order for the car, fully loaded including the 21 inch wheels (we tried to replicate the exact options on a coupe version we test drove at the dealer ... and loved, but needed more rear space for our dogs!). After a 3+ month wait the car only arrived at the dealer 48 hours before we took delivery, so I don't think any items had been swapped around before we took delivery. While the vehicle was having the tire repaired at another dealer we searched (again!) for the sealant and compressor. Armed with the input from this exchange, help from the local dealer, and the manual, we were able to find the compartment under the floor. Wow! We had been shown the (empty) slots in the open area under the floor and were told that was where the jack, compressor, etc were stowed, if the car was so equipped. I had even lifted that tray to see if anything was under it, plus I am sure I had seen the tow eye before, but maybe that was in another vehicle we looked at. Now the manual makes perfect sense ... although I'm still searching for the reflective vests in the door bottoms. Our take-aways from this experience are 1) our salesman didn't understand/know about run-flat capability when you move to a 21 inch wheel, and 2) no-one understands TireFit, starting with the statement in the build configurator and including 2 dealerships. Even the MB Customer Assistance number gave me the runaround ... they confirmed it was in the build, but then the virtual arm waving started, claiming it was so the information display could recognize the 21 inch wheels (pure BS).

Now I'm a little more confident about the car. While I don't have run-flats I do have sealant, which should handle the simple flats ... small objects penetrating the tread area. (I've had multiple BMWs, mainly Ms, both with and without run-flats. I concur the handling is compromised, but I've also punctured two run-flat tires hitting an Interstate pothole on a dark, wet night - which split the sidewalls - but I was able to limp a few miles to somewhere safe and dry.) I am still considering how I might get additional levels of security. The sales pitch for the ContiSeal technology appeals to my aerospace engineering brain ... I might just weaken and replace all 4 to get that feature. The only other option would be to find a space saver spare (from Europe?) which could fit under the rear floor and also clear the AMG calipers on the front wheels.

Thanks for everyone's insight and help!

 

Glad you got your truck fixed but like everyone stated, you should have had a tire kit in the trunk.

 

Whats an Aerospace engineer doing in Union Kentucky? The two just don't go together ie aerospace and Kentucky

 

Contiseal is actually pretty cool, it's like a band of jelly inside the tire that will fill/plug the puncture to avoid using a temporary sealant, which makes a mess, or run flats, which suck in general. Aside from the cost, they are heavy like runflats but the extra weight is in the tread area, as there's a layer of goo in there, instead of the sidewalls. That's probably why MB doesn't use them OEM. I know VW uses them for sure, I've replaced them before for customers when I was with Firestone.

 

Something weird happening with my location! I was there this week doing consulting (northern KY/southern OH is big in aerospace), somehow my location got auto-updated.

 

Thanks for the feedback. By not putting the sealant on the sidewalls they clearly retain the sidewall flexing performance of a non run-flat ... which is good. Interesting about being heavier. Continental use the same tread pattern, speed rating, etc whether the tire is ContiSeal or not. But the hoop stress must be higher for the heavier ContiSeal tire, the casing is working harder ... surprised they say the dynamics are unchanged.

 

If they put it on the sidewalls it would just get thrown to the tread area anyway. It's a jelly like material, it wouldn't change the function of the sidewalls at all.

 

Not having a spare was on the CON side of the sheet when cross-shopping the GLC and Macan. I just like having the peace of mind when doing interstate driving. That said, I wonder if you could use a space saver from a Q5/Macan? I think both are 5x112 with similar offset?

 

I carry this in my trunk just in case. It has a jack, flashlight, Drill for removing tire and tire pump built in. I also carry a tire patch kit just in case I am outside cell service. It is made by Marchinn if interested. Bought it on Amazon.