I've heard nothing good about run flats.

After 2008, the new "R's" come with run flats to accommodate the urea tank taking the place of the spare.

Would anybody dare run without run flats for the sake of using a better tire?

 

The only R model to come with run flats is the BlueTec version, for the reason you mentioned above (to make room for the urea tank). The gas version of the R class still has normal tires with a space saver spare.

 

FYI, I am PERFECTLY happy with my run flats. 7 months in, and I have NO complaints about these tires whatsoever. If I can get them for a reasonable price, I will very likely buy them again, when the time comes...

 

My brother in law has a flat tire (RFT) on his BMW 325i and he had to replace all 4 new RFT tires not one (the other three tires were low on treads) because his BMW dealer refused to fix it.
C/P:

Here are some disadvantages of using run-flat tires, cons that turn into pros of using a regular tire:


1.The run-flat tires (RFT) can usually not be repaired in the case of a puncture, so instead of a simple puncture costing $20, you’ve got to replace the whole tire.
2.RFTs can malfunction, defeating their intended purpose to begin with, or be damaged in such a way that getting the typical 150mi@50mph is no longer possible.
3.Run-flats are more expensive to buy, more expensive to install and offer poorer performance.
4.Lifespan is half of that of normal (even with regular monitor of pressures).
5.Costs 50% more than normal tires on average.
6.The ride is more uncomfortable, especially if you have 17″ upwards.
7.Increase the running costs of ownership. Normally a tire lasts you a good average of 50,000 miles (80,000 km).
8.Not all tire shops have RFT
9.Unpleasant ownership as you always have to worry about getting a puncture and always hoping that the warning does not appear.

 

The biggest reason runflats have to be replaced rather than repaired when flat is that they've been driven on flat.

The "promise" is that the tire won't come off the wheel ... not that the tire won't be ruined.

Other problem with these runflats is that the liklihood is VERY high the only place you'll find replacements is at your Mercedes dealer.

And, if you're "out in the boonies," i.e. pretty far away from your dealer, you'll be getting a new tire FedExed to you at that location. This may entail a motel stay and meeting some nice rural people.

 

Good information - keep it coming.

 

take a quick peak over on one of the honda odyssey forums about the massive problems w/ run flats and the class action lawsuits over them...i agree w/ the posters above; try getting just one replaced when you are somewhere off of the beaten path. i have a close friend w/ a new toyota sienna who had to spring for four new non runflats when he ruined one run flat on a weekend coming home from vacation. no shop w/in 100 miles had a replacement on a saturday. ouch...

 

Interesting discussion. I bought Michelin run-flat winter tires in 255/60-16 for my S90 Volvo last winter. I've kept them on since then because they handle (corner, brake) 100% better than the Continental all-seasons I normally use in the summer.

I picked up a screw in the tread of a tire a few weeks ago and it lost pressure. I noticed it because the lower pressure affected the handling in turns. I took it to Sam's Club where they were able to patch the hole, reinflate the tire, and balance it satisfactorily. I've been driving on it daily since then (approx 50 miles/day at up to 70 mph). As for cost, they cost me US $106 each at TireRack, about $3 more than the same compound and tread pattern as a non-RFT.

I haven't checked RFT prices in 18- or 19-in tires suitable for an R-Class. According to the posts here, such prices are more expensive than non-RFTs. TireRack is an excellent source for R-Class tires. I've bought two sets of Max-performance summer tires (Michelins, worn too low from autocrossing to last more than two summers) and current set of Pirelli PZero Rossos in 255/55-18. I use Michelins in the winter (non-RFT).

In checking data on Vettes and Bentleys, I notice some of them come with RFTs. Owners of such cars may not be too inconvenienced by having to hang around overnight while a new tire or set of tires is Fed-exed when one goes bad. If I could afford my dream Bentley, I'd have the backup airlifted to me while the tires on the first were being replaced.

JR

 

Let's clear up some confusion.

Having had an Odyssey Touring for 3 years before the R350 (Touring trim gets runflats) they are NOT the same as conventional runflats. My 05 Corvette has conventional runflats. The difference is the Honda uses an exclusive Michelin desgin, called PAX, that uses an inner support ring (like a rigid inner tube if you will). The purpose of the ring is to allow a softer side wall for a good ride and yet provide the needed stiffness for driving with 0 psi air pressure. The harsh ride and noise of runflats are mainly attributed to the stiffer sidewalls for support. The excessive tire wear is attributed to the use of softer rubber compounds to try to offset the harshness of the stiffer sidewalls.

Another exclusive feature of the Honda/Michelin PAX is that it is not a conventional size but uses a metric diameter. So you are stuck with the Honda wheel and Michelin tire. The tire and casing together weigh in excess of 75 lbs (it is an 18 inch wheel equivalent diameter). Over 25k miles, I went through 2 sets of tires driving on rough concrete Houston pavement. When new, the ride and noise are acceptable and perhaps only bothersome to the most discriminating drivers. So, the desgin has merit. The problem is execution - the tires wear fast and get noisy and rough in under 10k miles use. I noticed considerable harshness in about 5k miles of use in which it wore down to about 70% tread depth in that time. Another frustration with the Honda/Michelin is that only a few places in the fourth largest city in the U.S. could service them. Three Honda dealers, two Nissan dealers and four indies. And yes - they charged premium. The "cannot repair a runflat" notion is urban fiction - they can be patched. But - catch a nail near the sidewall - and not only do you have to find a PAX certified tire shop, you willl have to buy a new $300 tire and a $110 support ring plus labor. Whew - nearly $500 if you catch a nail. And unfortunately for the PAX, to patch a hole, you have to buy a new support ring too!

Now for conventional runflats on my Corvette. They are standard size tires on standard size wheels so I can freely interchange with any brand size wheel and tire that meets the correct dimensions. In fact, I have 2 other sets of wheels and tires for that car that are not runflat. I use those for racing. When I drive on those, I carry a flat inflator kit just in case I catch a nail. For conventional runflats, since there are many manufacturers, and a growing list of them too, you can likely find a runflat tire to fit the R that is better than another brand. Conventional runflats are repairable with an appropriate inner patch - no Walmart plug kits. Discount Tire is happy to patch runflats.

Coming over from the Honda wtih runflats, my wife liked the runflat safety so much that she insisted we put runflats on the R Class. We did. The Michelin Latitude Tour ZPs are probably some of the best on the market now. Yes, they put out a bit more noise especially on the rough concrete here. And yes, they are perhaps a bit more harsh on bumps - especially jarring potholes. But they are nowhere near the noise level and harshness of the Honda/Michelin PAX system. On the Odyssey, you feel like you shattered a tooth filling when you hit deep potholes. Nowhere near that bad on the Michelin Lat ZPs on the R350.

As for tire wear with the Lat ZPs, after one year and 8k miles, wear bars are down a bit over 1/32 inch. Very acceptable for any tire.

Another benefit of the runflat on the R350, I took out the spare - and we now have a huge trunk too.

The premium price for runflats is a choice - the added convenience and assurance of runflat technology. As long as it is a choice - it is great. But when you are stuck with the same brand and limited service options like the Honda/Michelin PAX, you are asking for trouble. The person who bought our Honda Odyssey promptly replaced all four tires and wheels with conventional tires.

 

+1 Well said.

 

New E350 Blutec arriving mid-August. After reading the above posts, I am wondering if anyone could tell me if it would be possible just to put regular air tires on the car? Or, is there a "repair kit" to fix a RFT if I'm on a trip, etc.

 

I accidentally purchased these off of ebay for my R500 a couple years ago. At the time, I didn't realize that ZP stood for Zero Pressure...hence run flats. Anyway, we mounted them and let me tell you, they were like riding on stone wheels. Every bump, every undulation, every road joint was felt inside the cabin. They were absolutely horrible, as far as noise and ride compliance. These happen to be OEM tire for certain BMW X5s, so I listed them on a BMW forum and sold them. Cars that come with runflats from the factory have their suspension tuned for runflats, to help with ride compliance. My airmatic equipped R500 hated them, as did I and my wife.

Put a proper set of high performance all-season tires on her after that and all was well with the world.

 

Thanks so much for taking the time to send the above reply! I have forwarded it to the dealership and asked for their suggestions prior to the car arriving next month. Should be interesting to see what I am told.

I guess I am stuck with whatever tires the car arrives with? The invoice states: "R66 extended mobility tires" and "R48 17" 5-Twin spoke allow wheels".

The main two questions that I "think" you have answered are (1) Is there a kit to patch a RFT and (2) can regular air tires be mounted.

 

Just understand that--if the tire isn't too damaged--flat repair is just like any other tire.

NO tire manufacturer approves anything but patch/plug installed from the inside.

So, no "kit" for you, but you can try some of the tire sealant you install via the valve core for a temporary fix. This may, however, prove permanently fatal to your tire pressure monitor sensor, which will be $200, thank you.

 

Looks like, if all else fails, the best option is to trash the RFT and put on some good "regular" air tires. Wonder if anyone out there has gone this route?

 

It's an option that means you need a spare tire.

 

One of the service writers at the dealership has indicated that it says on the can of “fix a flat” – “tire sensor monitor safe”.

This would seem to clear up the problem of being on an extended road trip and having a flat. At least it is a solution. Not knowing at this point in time what brand 'run-flat' tire will be on the E350 Blutec, how would I go about determining which 'run-tire' has the best rating?

 

Boy - I don't know what I would do if I got a new BlueTec.

I love these diesels and will buy another one.

But - I don't know if I'd go with run flats. I'd probably switch them out and also buy a 5th tire/rim to carry with me.

Tough one.

 

I thought the reason the Blutec had runflats is because the AdBlue tank is in the spare tire well?

 

My story is very similar - I purchased 2 ZPs accidentally on eBay to replace unrepairable regular Latitues. Mounted them at the front where the suspension has regular springs. My 2006 R500 did not like them at all - due to their heavy weight they were sending shock waves through the entier car after hitting road irregularities. I had to move them to the rear axle, the ride improved somewhat, but it was still very annoying - the rear air suspension did not like them any better then the front spring one. Lesson learned - avoid tires which have higher weight than the original ones, the R500 suspension is tuned at the factory to handle regilar tires only.

 

Goodyear approves one repair on their runflat tires. Most manufacturers shy away from stating they can be repaired at all for liability reasons.

I've seen more than a couple runflat tires missing whole chunks out of the sidewall and people still driving on them when they come to my shop. Runflat tires are designed to be able to run up to 50-75 miles with ZERO air pressure.

More expensive yes, poorer performance? Not necessarily.

That is relative, what are you comparing 'half of the life' to? You could have runflat tires on a Nissan GTR and be wearing them out in 10,000 miles. You could have runflats on a BMW 328i and they could last 60,000 miles.

This is valid only if you compare the same sizes, but even then there are some max performance summer tires that are just as expensive. Since I already mentioned BMW, we will use that.

The Conti Procontact SSR (runflat) sells for an average of $200 per tire. The traditional non-runflat Procontact runs about $120-140 (depending on H or V rated). But the Conti SportContact series prices easily match and in some cases eclipse the Conti SSRs.

6. If you have 17s or higher you are likely driving a more performance oriented model vehicle.
7. Yes, but it is relative still.
8. Yes, perhaps the only real drawback. But most shops can't afford to have the inventory space devoted to something that comes in once every few months. Nor would any want to risk theft, fire, or just sitting on the shelf too long.
9. You should always be concerned if any tire has a puncture. A leaking tire is problematic regardless of being a runflat or not.