Mitch Alsup

Let us postulate that this information is correct..............

We know that run flat ties have less traction than non run flat tires.
So, the above paragraph would indicate that you can never fix the suspension tuning by putting better gripping tires on the car.
Yet, those of us who have put grippier tires on our cars know this is not true--better tires helps everything {braking, acceleration, cornering--AND comfort}.

Q.E.D.

Joshua

thank you for this very informative and reassuring information.

thanks also to everyone else who contributed. I have sime work to do but my decision is clear. I shall go the non run flat path.

I will report back when this is done early jan.

merry christmas all.

this forum is great and has never failed us all.

joeyb1000

I had my dealer switch to non-run flats before I picked the car up.

I carry a plug kit, but not the Mercedes’ kit. Where I live, I am minutes away from a service station. So, barring a blow out (which seem more common on runflats &#128513, it’s unlikely that I would ever be stranded.

Joshua

Thanks Joey,

I have decided to get a set of Michelin Pilot Sport 4 seasons. About $500 AUD each. That plus a Puncture kit and I will be set.
I also have my indy sourcing an OEM 5th 20" Rim which will also get a 5th non runlet as a spare for my home garage.

ageeltm0

hi, how could you fit the spare in the trunk? Is there a space for it? (S560)

thanks

aeggroup

If you'd like to have a spare - the best solution is to buy a spare wheel from W221. It takes much less space in the trunk. Just don't forget to buy additional bolts that are different for spare wheels.

Joshua

Actually I never checked. In fact now that you ask the question my gut feel is the full size 5 Triple Spoke 20" rim with tyre probably won't fit. My plan is to keep the spare in my garage.

Donnymac

I can argue pro RF or NRF. Just know that switching to a NRF brings dimensional changes when mounted to your OEM wheel vs RF. Is that important?

Ive seen no negative comment from those who have swapped from RF to NRF.

Good luck.

aeggroup

Are you serious ? What dimensional changes ? Are you saying that RF tire has different dimensions that NRF ?

as.thompson

The "dimensions" don't change if you use the same size tires. What changes is the sidewall stiffness.

Donnymac

Read up on Aspect Ratio. Plenty of www to read.

try this link. https://tiresize.com/chart/

Merry Christmas boys!

Arrie

The cars used to have a “mini spare” or a ”donut” that was a lot smaller than the rea tire. I have this in my 2010 E550 and had the same in my 2013 S550. No errors if any kind with this stupid undersized spare on. You just knew you had it and had to drive accordingly.

The start of the run flats came with the diesels when they had to fit that Add Blue tank somewhere and that tank took the place for the spare tire. They then developed the Run Flat tires so you don’t get stranded when tire gets punctured. Car maker might get in trouble from this without having spare included with the car, you know…

They probably then realized how much money the car maker saves with not providing the spare so now they do the run flats for many cars and then try to force customers buy them with the total BS claim if car being programmed for run flat tires…total BS!!

Joshua

Easier said than done ... apologies in advance for this long reply.
I thought I would update as the OP on where I am at.

Over Christmas and with time on my hands I researched (and yes much over thinking and analysis) on preparing for a experimental replacement set of non-run flats.

My research included talking to ...
- a dealership
- a specialist "boutique" and yet high volume tyre shop
- a national franchise tyre shop.

- The dealership=gave me the same tired "we are not allowed to install non-run flats as your model is specially designed overall for the MOExtended Pirelli (it has RUN FLAT and MOE printed on the tyre wall) Zero tyres. You risk error messaged being thrown up to .... why would you risk non-OEM equipment on such a safety item on your car"....... when pressed with what might be the "safety" concerns .... and with the S65s having non-run flats... the conversation descended into a series of shoulder shrugs .......

- As to why I Have both MOE and RUN FLAT on my oem tyres is bewildering given that any Tyre with the RUN FLAT Certification (ISO) must be able to "run on a flat at 50 mph for 50 miles REGARDLESS OF LOAD AT ZERO PRESSURE vs am MOE "by design" only being capable of 50 mph for 50 miles under light load and 50 mph for 20 MILES under light load .......

So my decision to experiment in NON RUN_FLATs (wagering $2360 AUD @ roughly $600 AUD per tyre) has resulted in ......

- Australia does not have Michelin Pilot Sport 4S in stock. Xero. Nada. Zilch....
- Hankook - (note: Mercedes recently certified Hankook as OEM and MOE for its S Class amongst other models) do not actually do a REAR 275/35 R20 in Australia.
-Pirelli Zeros - no stock

In the meantime .....I am preparing for a non-run flat experience by sourcing ...

1. A simple and reliable / accurate analog tyre gauge.
2. A Tyre puncture kit with plugs, reamer, and the accessories (I am reasonable handy with tools and capable of a road side tyre repair ... I think ...)
3. A SUV rated 180 Litres / min compressor from an Australian 4x4 shop (have you seen what the mental Aussies do to their suv tyres when they go 4x4 driving in the Australian bush ?)
4. A set of 4 Kincrome plastic coated impact socket wheel nut sockets.
5. An extendable tyre wrench leaver for the wheel nut sockets or I might just use my Milwaukee 1/2" impact driver ........

6. The engineer in me wants to buy a torque wrench but it may be overkill ...

Now, if only I can get a set of tyres ... anytime soon ....

Joshua

PS: I checked and my car comes with the trunk insert for a can of goo and the Mercedes square oem compressor which I understand is not that great... and ....

I was "warned" that if I used the can of goo I risked an expensive replacement of not only a new tyre anyway but also an expensive (in Australia) TPMS sensor ... which Mercedes does not mention anywhere in their documentation !!

aeggroup

This is true. Avoid this stuff. In case of a leak the best solution is to have a good air pump and drive to the nearest tire shop. Sometimes you need to stop several times to put more air in a tire, it all depends how bad is the leak.
It happened once with me. Took me couple stops to drive to the nearest shop.

VII

The OEM tire sealant and many aftermarket are "sensor safe" so TPMS sensors will not be damaged if you get the right sealant.
Tire must be dismounted and sealant removed as soon feasible after use.
In the US "slime" is fairly inexpensive sensor safe and water washable brand.
​​​​​​

Joshua

thanks.

update: Tyres now ordered. Due next week. Michelin Non run flats Pilot Sport 4 S

will report back after fitting.

PS: for current W222 S560 owners - Any recommendations for optimal tyre pressures - ride and comfort bias. Max two persons including the driver. No luggage.

thanks

SW20S

I run mine at about 31 PSI

Joshua

Thanks SW20S.
31 PSI on 20" rim / tire combination ?

SW20S

Mine has 19s

superpop

You should really be following the tire pressure guidelines outlined on the sticker on the inside of the gas tank filler door.

SW20S

They make the ride too firm. I have been running lower pressures than whats on the filler door on cars for a long time and have never had any issue, no abnormal wear, etc.

In other markets the sticker on the fuel door says as low as 29 PSI for the 19s, running 31 is no risk at all. In the US pressures are inflated for fuel economy.

Joshua

the pressures on the inside of fuel cap are for the OEM Pirelli PZero run flats 20” rims.

i am now opting for NON run flats. Hence my question !

SW20S

No difference in pressure recommendations for RF vs non-RF.

DenysT

I thought it was different. Thanks for the advice.