Cao Black

Aside from having the correct lug bolt pattern and brake caliper clearance, I wonder what effect a compact spare might have on the 4Matic system.

threeMBs

Obviously it has correct 5x112 PCD, 66.56 CB and of course it clears the brakes (it clears E450, so it will E300).

As far as effect of using compact spare on 4matic. Your signature lists ML350, what do you think its spare is? It is compact. Using compact spare on W213 is identical to its use on W212, and all other MBs, 4matic or not. The answer is none, unless one uses it continuously for hundreds if not thousands of miles (which is not possible because compact spare tire will get destroyed well before that).

For those driving mostly in cities or urban areas, compact spares fine. If I were to drive in the middle of nowhere, as a couple of poster indicated above, I would buy only a full size spare as I suggested and explained above.

More info here:https://www.tirerack.com/tires/tiret...jsp?techid=141

JTK44

Just my $.02:

Nothing: up until the present E Class, doughnuts were supplied in all cars including 4Matics.

Doughnuts are now an option on BMW 5 series. xDrive.

Audi A6 does not offer RF.

Remember the main, and I believe, only reason for elimination of the doughnut spare is to save weight, about 50 lbs, which reduces CAFE.

Before anyone laughs at the weight savings and fuel savings, remember when Audi went to aluminum for hood, trunk and other body parts, at great expense to save just 150 lbs? So saving 50 lbs by eliminating the spare does make a difference in CAFE.

threeMBs

Compact spare wheel with tire for W212/C218 (and for W213, if they made one available for the US) is under 25 lbs. RFT always weight more than their non-runflat peers. I think its the combination of cost savings of having no spare and "packaging" (what they can put in the rear since they do not need that room for spare) more than anything else.

ua549

Run Flat tires cannot be repaired by any reputable service provider because repairs to RF tires are prohibited by the manufacturer. Having a RF tire repaired is about as risky as asking to have pollution controls disabled. Anyone who does so is taking on a big liability.

Helmar

JTK44

Just once again my $.02:

I have had RF and there was a flat, nail and it was repaired and I drove the car and tire without incident for another 20,000. I kept the tire inflated so that it never was on the sidewalls.

If the RF does go flat and you run the tire on the sidewall then you cannot repair the tire. But ordinary flats caused by nails, etc. can be repaired just like normal tires.

Weight: when you add the weight of the tire, the wheel and the jack it is more than 50 lbs. closer to 60 lbs. Each RF weighs 3 lbs more than a non RF. That is an overall savings of between 45 and 50 lbs.

Replacing tires: I disagree: 8-10,000 is only 1/4 of tread life. Only the most sensitive of drivers will ever notice the difference. In fact when I turned in my 2016 E350 the tread on the rear tires was 2/32 less than the tread on the front tires. 2/32 to 3/32 is about the tread wear of 8/10,000 miles.

In any event if you are that worried just replace the tire on the opposite side - no need to replace all 4 tires unless you own stock in a tire company!

threeMBs

Good point, but not always true for MB's 4matic. Several 4matic models are offered with staggered wheels/tires (i.e. W213 E63 - 265/35-20 front, 27.3" diameter and 295/30-20 rear, 27" diameter). Normally, MB 4matic has tolerance of at least 1% front/rear diameter differences. So in many cases only two tires are required to be changed.

threeMBs

Just weighted my W212 E550 OEM spare wheel with mounted 135/80-18 (https://www.tirerack.com/tires/tires...omCompare1=yes) tire. Exactly 30lbs. W166 ML jack (this is the one that must be used with W213) is 10 lbs. Total 40lbs (not 60). Subtract extra rotational weight for RFT and one ends up with saving of 25-30lbs. Add extra drag of heavier rotational mass... so CAFE only reasons make less sense to me. There has to be more in the decision to use RTF than CAFE. Cost savings (that includes dispatching roadside assistance, remember how MB significantly cut down on it a few years back?) and packaging I would think are the primary reasons.

Helmar

I had understood that this was a "damage to the car" issue, rather than a "driver experience" issue. If it doesn't damage the car, then that's good.
HBH

threeMBs

Correct. No damage to 4matic car. The difference between new tire (typically 10/32) and legally worn tire (2/32) is only about 6mm. That what the front to rear tolerance for MB's 4matics is - from 6mm upto 1% of the original tire's diameter (this of course varies by models and is greater for SUVs since their tires have larger diameter).

ua549

I've had 2 flats on my E300 both of which could have been repaired if they were non-RF tires. The first flat happened when the car was a few days old. My regular tire shop refused to repair it and directed to MB because they did not have a suitable Pirelli replacement tire in stock. My dealer gave me a new tire and explicitly stated the Pirelli does not allow repairs to their RF tires. If they discovered a shop had repaired one, it could lose their franchise.

JTK44

Pirelli is one of the few manufacturer's that does not recommend the repair of their run flats. Pirelli gives a free replacement if first year or less than 3/32 of wear.

In any event most RF, provided that they have not been driven extensively and still have air in them can be repaired.



This is from Tire Rack.com:

Manufacturer/Brand Repair PolicyAdditional Provisions

BFGoodrich Permitted 1 repair maximum

Bridgestone Permitted Only if 15 psi maintained

ContinentaL Does not recommend Mfg. Road Hazard Program*

Dunlop Permitted 1 repair maximum for H- and greater speed ratings

Firestone Permitted Only if 15 psi maintained

Goodyear Permitted 1 repair maximum for H- and greater speed ratings

Hankook Permitted

Kumho Permitted

Michelin Permitted 1 repair maximum

Pirelli Not endorsed Mfg. Road Hazard Program**

Yokohama Not to be repaired if run-flat

*Replaced free of charge first year or first 2/32" of wear (whichever comes first). Continental advises that a repair to one of its tires invalidates all other manufacturer's warranties.
**Replaced free of charge first year or first 2/32" of wear (whichever comes first), then prorated until worn to 2/32" of remaining tread depth.There are many links that clearly indicate that RF can indeed be repaired:

see: https://www.tirerack.com/tires/tiretech/techpage.jsp?gclid=EAIaIQobChMIpq3zwcfz3wIViuDICh1 zYgf8EAAYASAAEgKdufD_BwE&techid=226&ef_id=EAIaIQob ChMIpq3zwcfz3wIViuDICh1zYgf8EAAYASAAEgKdufD_BwE:G: s&s_kwcid=AL!3756!3!304470776799!b!!g!!&affiliate= HM5

Frank Rizzo

+1. My E43 has 245/35/20 F and 275/30/20 R - just as an FYI....

.

etaynor

Hi All, My solution was to buy a matching rim, a 5th tire, second hand jack and lug bar. It takes up most of the trunk space. When i'm local, there are 4 MB dealers within 50 miles of my house. Then, i take the tire out of the trunk. Otherwise, if i have an appointment, or going long distance, i replace the tire and have a spare. I was advised not to add the multi hundred dollar sensor on this fifth tire in as much as it would disrupt the car tire pressure sensors. I look at it as a comfort insurance amortized over the life of the lease.
After driving from NY to San Diego ( in another car), I realized that i would have been in real trouble if i had a tire issue out west. Just sayin'

jl199986

What’s that cross beam for anyway? Stiffness? I was surprised to find it there - thinking there should be a little more room the footwell for the jump seats. With that they’re completely inadequate. Given it’s a raw piece of metal it almost seemed like a shipping bit, out of place with the rest of the finish in the interior, even for being hidden for the rear seats. but I think it’s permanent.

gfmohn

The ContiComfortKit has been replaced by the ContiMobilityKit.

2thfxr

I just dropped my E300 at the dealer to have map upgrade done and I asked about purchasing a donut spare tire. THey said there was none to buy. I said I was concerned about the long distance I would be from the nearest MB dealer driving Denver to Phoenix and SW said not to worry, he has seen people drive close to a 1000 miles on one of these RF tires that was out of air. I am sure that tire was not usable after that but at least they were able to continue to drive, I bet the dashboard was squawking the whole time.

threeMBs

I would take it with a huge grain of salt. I suppose it is possible with a slow leak from a small diameter nail/screw in the tread, but what if there is a severe (pothole or similar caused) damage to the sidewall resulting tire to come off the bead? IMHO, spare is your friend not overly optimistic service writer/"advisor".

JTK44

Many thanks for all the advice and information. I went out and looked again at the well in the trunk and I agree, it would not be possible to put even a doughnut (compact spare) there.

I really do not like the idea of cleaning the tire and rim and replacing the TPS so the "fix it in a can" solution is out. (probably would not be able to clean the tire and would have to replace it)

What I have decided to do is buy a medium quality air inflator and keep it in my trunk. If I have a slow leak, for example a nail, the TPS will notify me and I will stop and use the inflator to keep the tire pressure up high enough so that I am not riding on the sidewalls and thus destroying the tire. When I reach my destination I will then have the tire fixed. As mine is a Perilli, they are warranted for 1 year with a free replacement. If beyond a year, I will just have it fixed by an independent tire shop.

If I have a blowout, then the RF is good for 70 to 100 miles and that should be enough to get me to somewhere that has replacement tires.

Of course the best solution was to have Mercedes equip the car with a doughnut and if not to just buy a spare tire and wheel, but I do not want to give up the trunk space.

Here is link to the tire inflator I bought: https://www.homedepot.com/p/Husky-12...120B/303815464

rbrylaw

This is the one I bought and it has close to a thousand positive reviews on Amazon. I've used it add air to our tires during the recent cooler weather and was pleased.

stephos

That's a good shout, I should get myself a compressor and keep it in the car - just in case!

nycebo

I got
which included a bunch of tire repair products. However, I haven't used them so can't comment on their efficacy.

threeMBs

Portable compressor is a must in any car (very helpful with a slow leak, run flat or conventional tire), however it is useless if there's a total failure (where only the spare will do). As far as how far one can drive on MOE branded tire with a total loss of pressure, this offers an eye opening read: https://www.tirerack.com/tires/tiret...jsp?techid=234. (As per TireRack it is 50 miles max (only 20 miles for a fully loaded car), not a thousand miles that was posted somewhere above as per a Mercedes Service Writer).

twistedtree

I had a flat on the run flat on my BMW, and it really opened my eyes to how totally useless run flats are. You get a flat in the middle of nowhere, 7pm on a Friday, and the closest dealer is 100+ miles away. What ever you have planned for the next 3-5 days, you can now throw away because you will be in a hotel waiting for a tire. And that assumes you are lucky enough to end up somewhere where there is a hotel.

So at 7pm Friday you call for help, assuming you have cell service. There are large stretched of the US that don't have cell service, by the way. But we will assume you are lucky, and it takes the tow truck 2 hrs to get to you. Now they tow you another 2 hrs to the dealer. And where is your family of 4 sitting for this tow ride? Are all of you and the driver in the front seat of the tow truck? Are you all sitting in your car on the back of the flat bed? And don't tell me to get a cab. Remember, we broke down in rural America. There are no cabs. And even if there are, I'm paying for a 2 hr cab ride?

OK, tow truck dumps car at dealer, now you and your family need to find a hotel and somehow get there.

Even if the dealer is open on Saturday, they need to order the tire. Order gets placed on Monday, and at the very earliest they get it Tuesday.

With run flats, a flat cost me and my family 4 days of time, and probably $1-2k between hotels, food, cabs, and the silly tire.

Now compare to having a full spare. 30 minutes max on the side of the road and you are back in action with little to no disruption to your plans. And at your convenience, you stop by a tire shop and have them mount a new tire and swap it back onto the car and return the spare to the trunk.

What benefit does a run flat bring other than costing me a shirt load of time and money?