ecohen2

Last week I managed to get a nail dead center in one of my run flat tires. Much to my surprise both Mercedes and the tire dealer told me that run flats could not be patched, which mean't that I had to replace the tire. Of course the tire was worn enough that I would have to replace both the rears and because I have a GLK25 4matic they recommended I replace all 4... Fortunately the leak was slow which gave me some time to think about the situation.

I decided to give up on the run flats for a couple of reasons. First, I had them on a BMW and the ride was horrible. I have never been happy with my GLK 250 compared to my GLK 350 and suspected it could be the run flats. That assumption appears to be true, I need to drive it some more but the wobble sensation is gone. Second, not being able to patch a tire in the DC metro area is just wasting money since the roads are so bad here. Third, if I do get enough of a flat that a small compressor can't get me to a garage then I am calling a tow truck anyway... The GLK250 does handle considerably better probably just because these are good quality Michelin tires..

Two questions:

1. Does anyone know if I should be running different pressure with normal tires vs run flats? The car says 33 all the way around, I just set them at 33 in front and 35 in back..

2. I don't plan on buying a full size spare but has anyone else tried a mini spare in the back? Will it fit in back? If not, I am just doing a compressor and a can of fix-o-flat...

Loving my GLK 250...

Thanks,
Ed

bugelrex

Which tires did you end up getting?

BTW, runflats can be patched or plugged if you find small indy store.

ecohen2

I put on Michelin Premier LTX... Not cheap but highly rated for the type of east coast sloppy weather.

I actually visited and called around for a couple of places. I am thinking because this metro area is SO over the top with inspections that nobody was going to plug the tire. The shop that did my other tires explained why you are not suppose to plug a run flat. Apparently the material used to make the tire super stiff gets a crack when it gets punctured. If you plug it, that material breaks apart even more and usually won't seal around the plug.

​​​​​​​Ed

ecohen2

After a couple of hundred miles I can say the difference is overwhelmingly positive. No more shake from side to side, smother ride and much better cornering...

B737

the Michelin Premier LTX is a great tire. i installed these on the GLK a few months back. they are smooth, quiet and grippy in wet weather. I look forward to installing the truck version (defender) on my tundra soon. removal and install + balance was around $900. The old tires lasted around 30,000 miles, GLK seems to eat tires, I guess most European cars do.

to answer your question just set them at what feels comfortable, i use 35 on all 4.

ecohen2

I am trying 37 and it seems to feel great... I am continuing to like these tires.... I probably have 500 miles on them now.

Thanks,
Ed

bop11

Took me 50K miles to go through the Conti's. I hated them especially in the snow. Replaced them with the Michelin's last month. They seem better already.

107123210

In Canada, we didn't get run-flats. Just the AW Contis plus a compressor and some sealant. I bought a compact Vredstein spare plus a cover for it. n summer, I leave it in the back. Takes space, but fits easily. When we need the space around home, I just take it out and would reply on MBRoad service or CAA. On long trips withy just two of us, I put the spare behind the driver's seat. It fits there with the back seats folded down. Hope never to use it, but you never know just where you will be when you lose a tire. Only supposed to work for 50 miles, I think. Bought unused from wrecker, but still not cheap!

Juliet Sierra

Would like to do the same. Has anyone found a hinged spare wheel rack for the GLK250 like you see on some Jeep Cherokees, etc?
Uncomfortable enough with 4x run flats, wouldn't want to have 4x normal tires.
Not keen on the roof rack option (vertical clearance, fuel economy, awkward to access).
Thanks,
Jim

dealerss

I just traded in my 2017 GLA250 4MATIC for my 2015 GLK250 Bluetec. The terrible mileage in the GLA got me to go back to diesel (I had 3 VW TDI's prior to Dieselgate). I averaged 27 mpg by actual calculation using Fuelly which was nowhere near the EPA 33 MPG estimate on the GLA! But I am thinking of ditching the run-flats too. Just a bit nervous about getting a flat and not having a spare as I drive about 35,000 miles per year from CT to Queens 4 days per week. But I did have to replace 3 run-flats in the GLA in 40,000 miles because of nails, etc. so I am definitely not a fan. Maybe a good compressor and fix a flat will get me by?

Juliet Sierra

I got into a position where one tire needed to be replaced ASAP, so now only have one run-on-flat tire as a spare.
There were only a couple of choices available locally (no Michelins) so went with Pirelli Scorpoin Verde 99V.
Difficult to believe the improvement of the ride and the lack of low frequency road noise compared to the original tires.
But the maximum speed with a trailer is now about 10MPH lower.
5x mount and balance, 4-wheel alignment plus a wheel for the spare tire cost about the same as two run-on-flat tires mounted and balanced.
Jim

RetiredSD

I'm in agreement with OP. In San Diego, the surface roads can be quite rough here. I will switch to regular tires when my run flats are worn for a smoother ride. In my scenario, I'm in populated areas 98% of the time and am fine waiting for the tow service which is included in my car insurance premium. I'm retired , so no rush. With our diesel model and lack of room for a spare, it's understandable why it comes with run flats.Here's another thing I considered, if I can't patch/save a run flat, I intend to replace two tires with regular ones for economic reasons. I don't drive it like a high performance car with high G forces and I feel the ABS system can handle any grip difference when emergency stopping. I think that that there's no right or wrong answer, just personal preference and situation. No business will endorse mixing tires for fear of litigation and other business reasons. For the few who say don't buy a Mercedes if money is an issue, I'll give you my address so you can send me a check for cost difference LOL!

RetiredSD

Fix a flat might clog the tire pressure monitor. You'll most likely need to replace the tire sensor unit. $$$$ I carry a plug kit and a compressor. Not a perfect solution.
UPDATE: I googled fix a flat and tpms damage. There's a good chance that if you get the tire off and the sensor cleaned within 100 miles, you'll be OK. But I also read that, depending upon puncture size, fix a flat may not allow you to hold proper pressure overnight. Hmmm.

kombifan

I like tirerack for their selection and price...and also they include full replacement rod hazard for two years.

Might be be an option to look into.

Tbh. I have a gl...with a full size spare.
Ive used it once....and the person who installed it stripped the bolts on the axle because they didn’t use the right shorter bolts

I’ve had nails, but I get around it by throwing on a spare winter tire if it gets really bad. Rarely.
The shipping is so fast for tirerack usually that I get it replaced before the nails really cause an issue.

andreigbs

Add another vote for ditching the run-flats in favor of the LTXs; excellent tire. They make the car feel and behave like MB probably initially intended.

Call me a risk-taker, but I didn't add a can of sealant or an air compressor. I'd hate to gum up the TPMS with that stuff.

AAA roadside pays for itself if I have just one flat, and I haven't had one in.... 3 years? Including a round-trip Chicago-West Coast-Chicago 8000 mile national parks road trip.

Enjoy the Michies!

(Goes to find wood to knock on)

Bob338

I had an adventure with tires and posted here at the time. Should be available back about 2014-15. Mine was a factory delivery built to my specs. No option at the time for regular tires but dealer through whom I purchased, agreed to replace with regular tires if the run flats weren't satisfactory. When I returned I found no fault with the tires and left them. Had the adventure in Yellowstone when I hit a rock slide in the dark and flattened the "run flats". No spare. Turns out they put regular tires on mine, likely Canadian specs. Rather than change the tires, we negotiated to where they gave me a mini spare. The normal spare space is occupied in mine with the audio equipment so I keep the spare strapped to the left side of the cargo space. Fits perfectly. The only restriction is one end of the load strap goes to the back of the left rear seat so when you put that down for cargo room you have a mini spare that's not secured. Car was equipped with compressor when delivered.

The tires @ 47K miles are at 40% tread except for the replacement which is @ 60%. No complaints at all!!

Jennascopmom

So we just bought a '15 GLK350 4Matic, and dismayed to find it comes with run-flat tires. If we switch to regular tires, do we need to also purchase new rims to accommodate standard tires?

Oh, and HAPPY NEW YEAR from the noob!!

Bob338

New regular/standard tires go right on your existing rims. No changes at all, except the tires!

RetiredSD

Agreed, also never used tire "slime" with tire pressure sensors. With no spare tire it might be tempting to use. Carrying a tire plugging kit works for most punctures in the tread area.

Robuk

Do not use the provided tyre sealant as after use the tyre cannot be repaired, this dreadful solution turns a £10 puncture repair into the cost of a new tyre. I have a Merc C-Class coupe CGI which fortunately has a spare wheel, my 2014 Porsche Cayman 981 does not. For the Cayman I use a tyre repair kit from Ebay. ( https://www.ebay.co.uk/itm/11Pcs-Eme...AAAOSwGzNdoFNz )

The Cayman came without a wheel brace or side jack, I have acquired a new wheel brace and a side jack from an earlier car. Prior to the Porsche I had owned a 2015 SLK 200, this also came with no wheel brace or jack, but any recent C-Class brace and side jack will fit the SLK or later C-Class cars, the 2011 C-Class jack fitted the 2015 SLK. This is all to lower weight which might also reduce that dreaded gas of life CO2.

Jennascopmom

That's fantastic, thank you!

MarylandGLK250B

On the 250 there is no place for any kind of spare. Still, I do NOT regret replacing my run-flats with the LTXs. I carry slime and an inflator, and my AAA membership. After 25000 miles on the LTXs, nothing but good news -- much better wear, MUCH better ride and handling, and improved gas mileage. I monitor my tire pressure regularly while driving now.

andreigbs

Same tires here, love them. No flats or loss of air pressure, great handling and quiet at all speeds. Wouldn't go back to run-flats for anything.

hhggzz

I ditched the runflats too and have a better driving experience. w/r/t your question about the spare - I found a used collapsible spare on Hollander and had it shipped to me (about $100). It does not fit into the area in the back. I only bring it on long distance trips. With or without the collapsible spare - an inflator is needed. I also have a can of slime, since you never know.

Robuk

Wouldn't go back to run-flats for anything.[/QUOTE]
[QUOTE]
It appears that if you drive any distance on run flats they can`t be repaired as the inside of the tyre is destroyed, not for me thanks.