mis3

I was told that most new MB now come with run flat tires. Even if you want to replace all of them with regular tries, it is not a good idea because MB has adjusted their suspensions to work with run flat (stiff side wall).

What is your experience with run flats?

Glyn M Ruck

They are crap. Benz has actually had run flats made for them with softer sidewalls that won't run as far flat. The damn things mess up the the ride & don't last. In SA you can order your car without them & an inflation kit or a mini spare that lies in the trunk with a cover. People who get them new usually remove them pretty quickly. I can't stand them.

EDIT: I've just fitted a set of Michelin Pilot Sport 4's & I'm delighted.

mis3

Hence my questions.

1. I was told that MB suspensions are tuned for these tires (still have stiffer sidewall than regular tires). If you change all four to regular tires, would this impact the ride quality?

2. Since these are special MB tires, can you still get them from a regular tire store?

Rudeney

There is only one reason car manufacturers are going with run-flat tires: To reduce weight by eliminating the spare tire and jack so they can improve MPG and meet the (unobtainable!) 54.5 CAFE standards for 2025. Honestly, I wish they'd just offer free towing and forget the spare tire and run-flats. In my SL, the spare tire has to be inflated before use (it has an air pump included). The skinny little donut in my W209 was scary to drive on. In either case, I'd just rather get towed. Of course then the problem is getting towed somewhere that actually has a tire in the right size in stock!

mis3

So, this is crap. It will be hard to get replacement tires since they have to be MB specific. What are the chances that the local tire stores have these MOE in stock. Also, run flats are expensive and cannot be repaired!

Are the other car manufacturers going with run flats as well?

Glyn M Ruck

BMW took the lead with run flats. It's also a cost saving ploy. In SA your chances of finding the right tyre in the back of beyond is zero. The only answer is a call to roadside assist. Resistance to run flats is high here. We all prefer driving the cars on conventional tyres. However they probably make sense for safety of a single female driver out on her own in suspect areas!

mis3

I was told from MB that since the suspensions are tuned for these MOE, it is not advisable to replace them with regular tires. Any truth to this?

Glyn M Ruck

Complete and utter rubbish. Convenient & misleading dealer answer. The car handles & brakes better with conventional tyres. i.e. it is safer. Run flats need a lot more development before they can compete ~ if ever.

mis3

The dealership told me that since these runflats have thicker and stiffer side wall, MB has to adjust the suspension to work with them. If changed to regular tires, the ride quality will suffer.

I guess they try to persuade Mb customers to buy tires from them.

Glyn M Ruck

ConventionaL tyres will give you a better more comfortable ride.

mis3

You are lucky in SA. This is not an option in Canada.

On the other hand, to replace all 4 tires at our own expense would be expensive.

Rudeney

Forget finding tires in stock - runflat or not. No stores in town stocked all four tires for the CLK (225/45-17 and 245/40-17). Some might have fronts, some might have rears. Tired for the SL (255/35/19 and 285/30-19) are just about non-existent. No store stocks them, and few can even get them. Locally, I have a choice between 3 brands unless I want to go to TireRack.

gaazmon

I would definitely ditch the run flats and go with conventional tires once they run down. Run flats ride way too harsh for me and they wear so fast. Besides the money you save in the price difference you can most likely buy a spare rim and tire and you'd cover the cost. Lot of the E92 BMW guys replace theirs and buy the BMW spare wheel kit (the only issue on their models is there is no space for the spare in the trunk). Idk if other issues arise if the car has a staggered setup. I just hate how its so hard to find cars with a full spare anymore.

abqhudson

BS.

eteller

Like Gaazmon said their are a lot of unhappy BMW owners stuck with run flats. My wife hit something with her Z3 and I was in the tire store the other day getting a new tire put on and TWO BMW owners were complaining about the stupid run flats.

mis3

In Toronto, I have no problem to find my summer tires. I have been using 17 inch Pirelli All-Season for a long time.

In the winter, I run 16-inch and it is close to impossible to get the rears, 225-50-16.

mis3

I started to learn about these runflats because of my friend. She bought a new C coupe and had a flat 2 weeks ago. It happened in late evening and she somehow found a tire store which was still opened. They replaced the tire for $160CAN.

When I learned about the price, I found it too cheap. Sure enough, I checked the tire, it was a no brand name non-runflat. The brand is "Horizon" (???).

gaazmon

My brother has an E92 335i coupe w/ the M sport 19" inch wheels there are only 2 brands for that size in run flat variant: bridgestone and pirelli. I can't even find the pirellis locally stocked (except at the BMW dealers) and tirerack is back ordered till end of March for the front set. At this point I'm trying to convince him to buy the BMW spare wheel and tire kit for $500 bucks and put regular tires on (it'll pay for itself after two tire changes). I seriously think the whole run flat trend is for the car manufacturers to save on weight and extra parts to satisfy fuel economy ratings and pass the burden and cost onto the consumer

mis3

You will have to add $1,200-1,400 for the cost of the 4 regular tires.

The consumers are in a bad position with these runflats. Lets say the new car is a lease of 2 years, should we spend an additional $2K for the regular tires and spares? Lets say it is a purchase, what do we do with the runflats?

On the other hand, since these runflats cannot be repaired, one nail in the tire will cost $500!

The tire and wheel warranty is getting more and more appealing now.

Rudeney

BINGO!

Rudeney

Oh, and speaking of saving weight, did you know that the R171 SLK came with regular tires, but no spare? Just a can of fix-a-flat in the trunk. Well, that and the promise of MB roadside assist. My SL has a deflated spare. So they saved weight on the extra air, but had to add a compressor to inflate it? Nah, not really - it's a space-savings strategy, but it's still funny.

mis3

Below was taken from fixaflat website. If this is correct, who do we do in the winter? Apparently we cannot store this product in the car in winter.

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Frequently Asked Questions

Can Fix-A-Flat® freeze?
Yes, if the temperature falls below 32 degrees Fahrenheit it will freeze. The product in the can is not damaged and may be used after thawing. If the product is in the tire, and freezing weather is predicted, then immediately take the vehicle to a qualified tire professional for repair.
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Rudeney

Yet another good reason to live below the Mason-Dixon line Seriously, one thing you should never do is continue to use a tire with Fix-a-Flat in it. It's only meant as an emergency repair until you get to a shop that can properly fix the tire. And of course it does no good for anything more than a simple tread puncture.

I did go through the exercise of inflating and mounting the spare in the SL just so I'd be familiar in case it was needed. Its spare is wider than the usual "donut", but it's still pretty flimsy feeling. Honestly, unless I were just a few easy miles from home, I think I'd just call for a tow.

gaazmon

On a lease it wouldn't make sense since you have to give the car back with run-flats (I don't think there is a way around this, it's part of the contract, at least that's what my friends that have leased cars with run-flats have told me). In case of a purchase, I would just drive the run-flats down to the point of needing replacement then replace them with regular tires and buy the spare kit.

JimVonBaden

That is how my 08 Saturn Sky Redline came. No spare, a compressor with fix-a-flat slime in it. I bought a spare wheel and tire and keep it in the garage. No room in the car for it.


On my CLK 500 I bought new tires last year when I got the car. A set of Sumitomos from NTB for just under $600. Great tires, the car rides excellently, and handles well.


Run flat tires are a pain in many ways. Once flat they must be replaced. They are very expensive. Often, if you have much wear on one, when you replace it, you have to replace the other three. Screw that!