Run Flat Tyres

[Gramps48]

Hi – I’m new to the forum and this is my first post. I have a S205 and I love it but it now requires a complete set of tyres. Existing tyres Pirelli PZero MOE, 225/40/19 93Y on front and 255/35/19 96Y on rear. So far I have only been offered PZeros or Continentals as a set of 4

I have been given the options of different manufacturers on the front and rear axles although I feel uncomfortable about that – probably just me !

Another option offered is to change from run-flat to conventional tyres as, it is claimed, it will offer price savings and improved ride. However, this would mean a space saver taking up luggage space or simply relying on a can of repair sealant.

OK, I have to make my own decision but before doing so I would welcome any comments /advice



Thanks

 

[GeeJayW]

Been grappling with this one for a while myself. Still currently on the same MOE Pirellis you have, but may well go to 18" five-spoke rims with normal MO tyres.

 

[Gramps48]

Been grappling with this one for a while myself. Still currently on the same MOE Pirellis you have, but may well go to 18" five-spoke rims with normal MO tyres.

I had a choice of two when I bought the car, the other one had 18" 5 spoke wheels but the overall spec was not quite as good.

Would you get a space saver or rely on a can of sealant ?

PS - got a MX-5 too !

 

[CJD]

Sorry, duplicate post.

 

[CJD]

I have the same 19" runflats on my car, for what its worth I think the you are better getting runflats again.
Carrying a spare in the boot, isn't very practical when you don't have a specific place to to keep it.
Plus if you do, where do you put the full size wheel & tyre when you have swapped out.
The can of gunk in my opinion is fairly pointless, as it doesn't really cope with much more than a slowish puncture from a nail / screw etc.
So runflats are far from ideal, but at least give you the peace of mind of being able to travel for about 50 miles, to get help in an emergency.

 

[rf065]

Mine came with 19" Conti runflats, recently changed the fronts for runflat Goodyear F1's, mine has airmatic so I don't mind runflats at all.

 

[GeeJayW]

I'm thinking of going to 18" due to poor pothole tolerance so far experienced with 19". We had a tyre damaged earlier this year and both front rims currently have slight flat-spots (again). Plus 18" regular tyres are half the price of 19" run-flats, which given they don't seem to last much beyond 13k miles is a useful saving.

As for a space saver, with Premium Plus spec, larger fuel and AddBlu tanks, there is no space for a spare much less the full size (punctured) rim and tyre just taken off the car. So a so-called tyre-fit gunge kit or recovery for proper blowout are probably the only practical options.

 

[190]

Anyone actually driven 50 miles on a punctured run flat ?

Serious question, I just wondered how much better they are in practice than a normal tyre and can of gung. I understand run flats are trashed by driving on them and you have to buy a new one.

 

[Gramps48]

I had a slow puncture in rear and when TPMS warning came up I topped up with 12v compressor. Pressure never dropped below 30psi so I kept topping up for a week or so though this was not a long term solution and a new tyre was fitted. I guess your comment about the run flat being trashed is correct which is why, I understand, they won't repair run flats because they don't know what damage may have have occurred in the sidewall - my punctured tyre may have been OK but no one could have known for sure.

 

[rf065]

I had a slow puncture in rear and when TPMS warning came up I topped up with 12v compressor. Pressure never dropped below 30psi so I kept topping up for a week or so though this was not a long term solution and a new tyre was fitted. I guess your comment about the run flat being trashed is correct which is why, I understand, they won't repair run flats because they don't know what damage may have have occurred in the sidewall - my punctured tyre may have been OK but no one could have known for sure.

If you never ran it flat it could have been repaired instead of a new tyre. The problem is finding someone prepared to do it when they could easily sell you a new tyre instead. All of the big tyre places will refuse to fix them but I've heard that a few of the smaller backstreet places are OK with repairing them if they know it was not ran fully flat.

 

[190]

Our attitudes to puncture repair are very conservative. In the US it's common for drivers to plug their own tyres at the side of the road using a reamer and kit of plugs. They sell these kits in all the supermarkets. Obviously the usual precautions apply i.e. no plugs in the side wall. Even if only viewed as a get you home repair it serves the same purpose as a run flat. They even plug tubeless motorcycle tyres and will convert tubed motorcycles to tubeless for the benefit of an easier fix at the side of the road.

Has anyone had experience with the aerosol gunge. I only tried in once on a tubed type tyre and it didn't do diddly squat except make a mess and annoy the guy who had to fix it properly but this was in 1975 so it might actually work these days.

 

[rf065]

Has anyone had experience with the aerosol gunge. I only tried in once on a tubed type tyre and it didn't do diddly squat except make a mess and annoy the guy who had to fix it properly but this was in 1975 so it might actually work these days.

I've heard it's a pain to clean it off before a repair can be made, your just as likely to be told you need a new tyre, not much different from runflats then!

 

[Ed65]

Hi – I’m new to the forum and this is my first post. I have a S205 and I love it but it now requires a complete set of tyres. Existing tyres Pirelli PZero MOE, 225/40/19 93Y on front and 255/35/19 96Y on rear. So far I have only been offered PZeros or Continentals as a set of 4

I have been given the options of different manufacturers on the front and rear axles although I feel uncomfortable about that – probably just me !

Another option offered is to change from run-flat to conventional tyres as, it is claimed, it will offer price savings and improved ride. However, this would mean a space saver taking up luggage space or simply relying on a can of repair sealant.

OK, I have to make my own decision but before doing so I would welcome any comments /advice



Thanks

 

[Ed65]

Hi, for me personally I would stick with rft - as with most safety components their value isn't really appreciated until they're 'activated'
(from experience)
.... The latest generation are much more compliant too.

 

[markjay]

As someone nearing the end of long career involving spotting weak points in designs (aka Single Point of Failure) , I always do the following, in the order of priority, and regardless of whether the car has run-flats or not:

1. Carry full-size spare in the boot where possible.

2. If not possible, then carry a space-saver.

3. If neither is possible, then carry a spray can and tyre inflator (and a good luck charm).

- Full size spare is the only solution that will see you continue your journey interrupted.

- Space saver will go half way towards that by not leaving you stranded at the roadside.

- Run flat tyres have the safety advantage that you may be able to avoid having to replace a wheel at the roadside. I say 'may' because if a tyre is shred or explodes than even with run-flats you could end-up stranded, though the risk of that happening is obviously reduced.

I currently have a full-size alloy spare on the W204 (the space saver it originally came with is in storage), as there's sufficient space for it.

For Mrs MJ's Suzuki I bought a space saver, because a full-size spare would have taken too much space (the Mercedes TireFit inflator kit the Suzuki came with - as result of a mix-up at the car dealer - is now in the W204 - a backup plan for your backup plan is always a good idea!).

In aviation, 'running out of options' is a polite way of saying 'crashed'. So, for me, it's always about having as many options as possible, under any circumstances...

 

[MikeInWimbledon]

Hi, for me personally I would stick with rft - as with most safety components their value isn't really appreciated until they're 'activated'
.... The latest generation are much more compliant too.

Intrigued by your comment, which I've vaguely heard before. I stopped driving BMW's for several reasons, but the main reason was dreadful ride quality on E90's and E61's. What are the "latest generation" of these tyres? Is any particular make better - for example Conti Sport 5's or whatever ?

Or have you got a link you can recommend on the subject ?

M

 

[MikeInWimbledon]

Anyone actually driven 50 miles on a punctured run flat ?
Serious question, I just wondered how much better they are in practice than a normal tyre and can of gung. I understand run flats are trashed by driving on them and you have to buy a new one.

I think I have - I had one go an an E90, back in the day, maybe in 2010. It was late at night and I was out of town, probably 40 miles away from home. All I knew was that the run flat pressure warning came on. I drove to a petrol station, pumped in some air, the pressure was very low, and I drove home very slowly (30mph). I took the car to the tyre guys the following day.

How did it feel ? No different to "normal." (A crock of sheet, basically)

From memory, they did replace the tyre. Can't remember if there was an option to fix. (You know what tyre boys are, they'll always flog you a new one.

I hate run flats. But then I hate modern hard suspension / tyre set ups. I don't understand why a 1970 Citroen DS rides better than most modern saloons.


.

 

[190]

I don't understand why a 1970 Citroen DS rides better than most modern saloons.

I'm sure they could make modern cars ride well if they thought their target customers wanted to prioritise comfort over sharp responses and sharp looks. I'm encouraged by some of the more responsible motoring journalists fighting back by giving cars with a harsh ride the harsh review that they deserve. But that hasn't happened until ride quality got to a ridiculously bad level.

I think one big difference is that in 1970 car manufactures wouldn't have dreamed of their target customers being in their 20's and 30's, now they do. Mercedes, BMW and Audi patently do and firm riding prestige cars are the result even though there is nothing prestige about a poor ride. We now have generations of drivers who have never experienced a car that rides well so they don't complain about what seems to be the norm. Why would they. The sad thing is even I've got used to a firm ride, having not experienced a car that rides well for nearly 5 years.

 

[rf065]

It's not by accident that today's cars mostly handle corners and brake extremely well compared to the thin tyred cars of yesterday with wallowy suspension. In fact, driven briskly at todays speeds, most old cars would have been downright dangerous. It's called progress, we just have to accept it.

 

[190]

It's not by accident that today's cars mostly handle corners and brake extremely well compared to the thin tyred cars of yesterday with wallowy suspension. In fact, driven briskly at todays speeds, most old cars would have been downright dangerous. It's called progress, we just have to accept it.

I do accept that the improvement in handling that is the trade off for a stiff ride but I'd like both comfort and handling. I've been in a BMW 1 series coupe that was so stiff it had to be driven slowly. That degree of stiffness was just plain silly and achieved nothing on public roads. Perhaps it's superiority would show on a race track but what's the point of that for a road car.