Take a hypothetical that I hit a pothole hard about two weeks ago with my front 19” Pirellii P-Zero. Car has been driving fine.
Then one day, I notice an inch-gash in the sidewall, about half an inch up from the rim edge, where presumably the rim edge had cut the tire. Through the gash, I can see a tiny bit of the belt inside.
If this was a normal tire, such a cut would be scary. But this is a “special” run-flat tire and the tire is keeping air at a constant 43psi (I tend to inflate close to max pressure for better mileage).
Now if this was a normal tire, I’d swap it out in a flash since my tire could blow out and lose air at any time. But this is a much-ballyhooed “special” run flat. And all you read out there from run-flat proponents is how “extra safe” run flats are, how you can drive 50 miles on a flat run tire while flat, and that a run-flat will not ever blow out “unsafely” on a highway at high speed (as they imply a regular tire will).
Take a hypothetical that I have a 50-mile each way trip into the city coming up at least 65+mph highway speeds to go with the traffic flow.
So I can ‘trust‘ my run flat to not blow out in a unsafe manner at 65mph because of those “super strong” sidewalls the run-flat guys always go on about, and the special run flat tire will get me back home safely since they can drive for 50-miles while flat too. No worries?
Right? That’s the run-flat claim set – why people buy them – now do I really trust it?
Enough to drive such a trip? And keep on driving, until it finally goes flat as its “run flat” name implies?
Am I good to go – because it is a run-flat?
Given that: I want to change out these run-flats when they wear out with Michelins. These are my summer-only set, where I also have dedicated snows I’ll be switching to in late December. Right now at 19K miles, all four summer Pirelli tires look to have one-third their tread height left.
I can see three options.
- Replace the one bad tire with a conventional Michelin tire that I’ll be moving all four tires to eventually anyway
a. Do I have to worry about circumference differences? Traction differences?
b. In my two calls to local NH tire shops so far, the two best reviewed shops told me they don’t “even have the special machine” needed to remove a run-flat tire from a rim.
c. So already there’s a problem right there. It’s not easy to take a run flat tire off the rim??
- Buy a new Pirelli tire from dealer to last while the other three tires wear down
a. Wasting two-thirds of the tread life on the new one
- Keeping driving the run-flat tire until it finally does go flat, as it and the other tires all wear down together
a. This tire was designed to run flat – so trust it to get you home when it finally does blow
b. Watch the gash closely if it gets bigger
c. Watch for any air pressure drops, aided by the TPMs
d. Some on web have said their run flats have lasted months with a sidewall bulge and/or cut, they were surprised how long it lasted, where the tread finally wore down as normal.
These run flats allow for different operating rules than the days of normal tires? Run it until it goes flat, and stop fretting about the gash in the sidewall, it’s a safe run flat, so just trust it, since it’s MEANT to be driven until it’s flat?
Would you pro-run-flat guys really trust it just because it is a “run flat” tire?
What’s my best option here – trust option 3 and trust the fact it’s a run flat? Would you trust in the run flat concept and not replace it?