[JohnRichardson]

Hi.
I am thinking of buying a new 2024 Mazda MX5 manual roadster. I have read that they are unsuitable for run flat tyres but as they have no spare this makes me nervous.
Does anyone have any knowledge or advice, thanks?

[Drivingforfun]

Unfortunately, I think it's just one of those things you have to learn to live with if you want to drive a modern car

It should at least come with a can of liquid that you squirt into the punctured tyre?

A few years ago I went from a Mini with runflats to a similar model that came with regular tyres but still did without the spare, I was apprehensive and looked into buying a spare but ultimately it would have been awkward to store it (if possible at all)

If it makes you feel any better, after a bad puncture a while back I felt a bit embarrassed calling out the RAC for a flat tyre but they didn't make any issue of it whatsoever, they got me a taxi home like any other breakdown and left my car at my local tyre fitter 👍

[Drivingforfun]

Another thing, aside from modern tyres being much more resilient, the MX5 is such a light car, I imagine you'd just fly over all but the worst potholes without much bother! 👍

[Rolebama]

Getting rid of the run-flats was the first thing I did with my current car. Harsh ride, noise and the thought of the cost of replacement was too much for me. I fitted steel wheels with tyres with a sensible sidewall depth and transformed the drive. I sold the alloys and run-flats foe more than the cost of 5 replacements.
FWIW: I have tried using a variety of the slimy concoctions supplied by manufacturers, and never had success. I was with the AA when spare wheels started disappearing, and the subject of these slimes not working was brought up at almost every staff meeting.
Further to this, there are some countries where a spare wheel is a legal requirement, so the majority of available cars can be bought with a spare wheel, but there usually a waiting list.

[olduser]

I think, anyone using a can of puncture repair will find when they get to a tyre place they will say they cannot repair the tyre due to the goo inside.

It's several years ago when that happened to me, the puncture was in the tread caused by a nail, so could have been plugged in the usual way, the inside of the tyre was a mess.
The only way to clean it was to use a solvent and wash it out but where does the solvent go afterwards?

Needless to say, I never did that again, cars without spares were off my shopping list.

[TC1474]

I have had to deal with the aftermath of this liquid tyre repair stuff on a number of occasions, and when I have attended forensic tyre courses with the likes of Dunlop and Michelin, you can see their eyes roll as soon as liquid tyre repair products are mentioned.

The first issue I came across (mainly on motorcycles but on cars as well from time to time) is how the goo can cause the wheels to become imbalanced creating wheel wobble as it counteracts the balance weights that were fitted when the tyres were balanced previously.

In some cases the imbalance can be quite severe (dramatic on the front wheel of a bike) and I have had a couple a fatalities where the cause of the crash (and subsequently cause of death) was attributed to the out of balance wheels caused by the liquid tyre repair stuff.

The other issue is the damage it can do to the inside of the rims. I have my own commercial tyre changing and wheel balancing equipment, so friends often get a set of tyres and ask if I can do the change for them.

The mess this tyre repair stuff makes is horrendous, and even though you can spend hours trying to clean it all off, even the slightest residue can prevent the tyre beading properly and you end up with a very slow air lea from the beading.

If the tyre id punctured within 50% of the centre of the tyre and the sidewall is not compromised, then it can be plugged and repaired using a vulcanised mushroom.

But..... Here again the goo stops the mushroom vulcanising properly, and so you run the risk of the original puncture hole continuing to leak as the mushroom starts to lift.

I could go on, but I am sure you get the drift, and as you might have gathered I am not a fan of liquid repair stuff, nor am I fan of the external repair kits where you push a plug in from the outside which runs the high risk of delaminating the tyre, especially on bike tyres, but I have seen car tyres blow from this as well which is worrying as by and large you do not get instant deflation as a rule as the air can only escape from where the hole is, but delamination puts paid to that theory and when they go, boy do they go as some of you more senior drivers might well have experienced during your driving career

[Mark07]

Originally Posted by JohnRichardson

Does anyone have any knowledge or advice, thanks?

There's lots of useful, real world knowledge in the discussion.

I also wanted to share RAC's Guide to Run-Flat tyres.