fmr

Just ordered a 2011 350 t oreplace my 2008 320. One of the things I noticed is that the new models now are equipped with runflat tires and so do not come with the spare - rep at dealer said bluetec tank takes up the space where spare would go. While I understand the value of run flats would be more comfortable having a spare, specially if I mount snow tires in winter. Has anyone found a spare tire option that wdoes not take up too much space?

lkchris

That would be the "spacesaver spare" fitted to other GL models.

43221B

I store a pair of pliers, a tire patch kit, and a small compressor under the floor in the back. I have patched several tires on other cars this way and have never had any issues. It is quicker and easier than changing the tire since you don't have to remove anything(other than the nail). All you do is pull the nail out with the pliers, ream the hole with the reamer, then shove the plug in the hole. I think the kits are a must for anyone taking long trips in any car.

For catastrophic failure, I purchased an extra 20" wheel to throw in my trailer since the compact spare wouldn't really be safe for trailering anyway. The tire patch kit should cover 95% of any flat problems though.

btw, One thing I really,really like about the Runflat concept is knowing that I can get off the highway to the nearest gas station in the event that I do get a flat. I do NOT like the idea of having a $70,000+ car with my family in it stuck out on some remote freeway somewhere waiting while I change a tire. Bad scenario IMO.

Texas993

That is exactly what I do.

dougpark714

I was surprised that GL450s and 550 with Run-flats come with Spares.

43221B

They have room for the space saver, so I guess why not? The space saver at least gives the 450 and 550 an option in the event of a total failure of the tire or a severely bent rim. Having said that, I would rather plug my 275/50/20s and continue on my trip than drive with a compact spare on my GL any day.

dougpark714

I always thought it was cool our BMW X5 had a fullsize spare complete with matching rims.

EWT

Run flats are ruined if they are "run flat" so you really need a spare even if you have them. Having a spare (or a place to put one) is a big plus because then you can replace those lumps of unsprung weight with real tires once they quickly wear out.

43221B

Could you please elaborate? Are we talking ruined after driving 30 miles flat at 55mph or are we talking 1 mile to the nearest exit.

EWT

The Bridgestones RFTs I had on another vehicle stated that had to be replaced if they were used with less than 15 psi in the tire, probably because the sidewall can potentially sustain damage from heat once the sidewalls are doing all the work.

43221B

I think the following Edmunds article on Runflats is a good read:

http://beta.edmunds.com/driving-tips...-a-primer.html

From the article:

Repairability — SST run-flat (Self Supporting Tire, which is what the Goodyear OE tires are) repair guidelines are nearly similar to those for standard tires. Michelin's PAX has more stringent repair procedures, including a warning that repairs can only be carried out at a "Michelin PAX System authorized servicing dealer." In either case, if the zero-pressure driving distance or speed is exceeded, the tire MIGHT need outright replacement. Furthermore, tire sealant-in-a-can leak repair products shouldn't be used, because they can foul many types of TPMS air-pressure sensors.

I used to work with a guy that was a former factory rep for Goodyear. His take on DIY tire plugging was that there is a very very minor risk (Goodyear legal dept. talking) that there could be internal tire damage due to the object that caused the deflation. He said that if you plug your own tires without a careful inspection of the inner tire that over a long time (probably longer than our Run on Flats will ever last), there is a slight risk of failuire. This is why some tire shops that aren't "manufacturer certified" won't plug any type of tire. They don't want the liability. Further, he told me that if you have any concern, you can take the tire after you've plugged it to a shop that performs the repairs and they can inspect the inside of the tire.

Having said all of that, I think you are totally fine plugging your own tire so that you can complete your trip. That's just my opinion though. Obviously, nothing is going to be as safe as a brand new tire.

lkchris

NO tire manufacturer approves "plugging" ever.

ALL require removal of tire from wheel and instalation of internal patch.

And, the special repair procedures for runflat tires is common--meaning "any old gas station" is NOT a solution.

lkchris

Not exactly.

The ONLY promise from runflats is that they won't come off the wheel and you can therefore drive (slowly) on them.

They certainly could be ruined by any amount of driving.

43221B

Absolutely, installing a "plug/patch" (not just an internal patch since we're being **** here) is the best solution. Unfortunately, my GL just isn't big enough to haul my family, luggage, and all the tire mounting equimpment that would be necessary to make such a repair 200 miles from nowhere at 10:00 at night.

I think the following article does a lot to clarify this debate:

http://classic.artsautomotive.com/TirePatch.htm

Also, click the link in the article to "doing things the wrong way."

EWT

Firestone says they're not repairable if driven with < 15 psi so if they go flat, they are no longer usable:

"RFT tires are not repairable in any of the following situations:

* If the tire is described as, "Do Not Repair" on the sidewall.
* If the tire was operated with inflation pressure less than 15 psi (100 kPa)."

http://www.firestonecompleteautocare.com/tires/faq.jsp


Carmakers like them because of the space that can be freed up by omitting the spare, but I'll never own a car with them again if I can avoid it. They wear faster, ride worse, handle worse, cost more and are a very temporary solution to a flat tire at best. Not much to recommend them IMO.

The PAX system is different than a traditional RFT because the wheel has an internal rubber ring that helps support the tire if it loses tire pressure. They ride and drive more like regular tires because they don't have the very thick and heavy sidewalls a traditional RFT does, but but they require special wheels and aren't interchangeable with any other non-PAX tires. They probably wouldn't be as likely to sustain damage from low/no pressure because the sidewall isn't forced to support the car.

43221B

Agree, to my knowlege though, all OE Runflats being placed on GL's (320/350/450) thus far have been Goodyear and I don't recall seeing a "do not repair" on the sidewall of my Goodyear Run on Flats. Ironically, if you go to the Bridgestone website, their FAQ section regarding runflats says nothing about the <15 psi limit. It is all about inspection which is much more practical than setting a psi limit.

www.runflat-system.com/english/qa/

The bottom line is that if you are buying a new GL350 or a 450 with the appearance package you are going to have Goodyear Run on Flats installed. You can read the links in the previous posts and decide for yourself if you want to plug, patch/plug, install a spacesaver, or call a rollback to pick up your GL. Your situation at the time of the flat will probably determine which method or repair you choose.

mdadgar

I have the 2010 GL brochure right here and Endnote #3 says:

Models with runflat tires are not provided with a spare tire.

- Mark

fmr

everyone, thanls for all the feedback. One of my oher cars is a bmw with runflats--my first -- and I do find the ride much harsher and noisier than with regular tires. This is the case even though I typically drive cars with low profile sport tires and believe they are still more comfortable than run flats. One other eason I would prefer a spar eso I can later change to regular tires on GL. For me this issue was a big deal when thinking about giving up the 08 gl320 for an 11 gl350. Unfortunatley as some stated above only option would be a space saver or regular sized wheel in the back cargo space as unfortunately there is no room to store it underneath.

lkchris

I think it's a culture clash.

In Germany, it's pretty hard to be very many miles away from auto service.

Where I live it's 60 miles to the next town, and I can easily get myself 100s if not 1000s of miles away from a Mercedes dealer.

dougpark714

Interesting.. I saw a 2010 GL550 and it had a spare..

dougpark714

I saw a picture of GL450 20" with Bridgestone EMTs instead of Goodyears..

dougpark714

Purchasing the mercedes tire/wheel protection for ~750 for 5 years may be worth it if you're getting the appearance package. I think you can buy it from any dealer and have it serviced from any dealer. Covers runflats even if you replace them from another place as long as it's OEM.

It's actually not a bad deal if you consider a replacement 20" goodyear runflat at $500 each.

Has anyone purchased this and experienced replacement process through the dealer?

revets

These are seemingly dufus questions compared to the technical discussion above. On a 2011 GL 350:

1. Can one replace the RFTs with regular tires when it's time for them to be replaced?

2. Can a single RFT be replaced with a non-RFT if there's a flat?

3. Does a regular tire on these rims require the same unique machine for RFTs to install?

4. Does anyone have a recommendation for a good patch kit?

The car we're looking at has Goodyears.

Great discussion. Thanks.

43221B

Ok, then per the other poster, don't repair your tires if they say "DO NOT REPAIR" on the sidewall. Case closed, problem solved.

43221B

You can purchase a plug kit at just about any auto parts store (Pep Boys, Advance, NAPA, etc.) It wouldn't surprise me if you could find them at Walmart. Just make sure that you have something to remove the nail (pliers, maybe needle nose to get between the treads if necessary) and I would also keep some wire cutters in your car to snip off the ends of the plug (there will be two since it folds over as you plunge it into the nail hole) so that it is near flush with the tread. The plug/patch kits are probably not going to be found in a retail store considering they require the tire to be taken off the wheel.

After plugging your tire, you could obviously take your car in at a convenient time, have the plug removed, tire inspected, and a plug/patch installed by a professional.

I have plugged several tires including a Goodyear (non-runflat) on my last SUV which got me another 50,000 miles out of the tire. I have never had a plug even leak. That's why I don't think you should be too worried about plugging a nail hole on a Goodyear runflat particularly if you are just trying to make it home.