A lady friend of mine recently discovered the downside to run-flat tires. They don't come with a MILEAGE warranty.
$1400 tires, I might add.
Run flats don't come with a MILEAGE warranty, specifically because they may be used in a run flat situation. You may be able to drive 50 miles on the tire, and if it's damaged in the process, get a replacement under the ROAD HAZARD warranty...
But after only 7000 miles, (versus 34,000 for the tires that originally came ON her SUV) her $1400 run flats were down to the wear bars.
Obviously Pirelli used an incredibly soft compound.
And you can't just replace ONE worn tire on a 4WD / AWD vehicle, as you know. They must all have similar diameter or you destroy the AWD mechanism, viscous clutch, whatever. So the Road hazard warranty is, essentially, USELESS.
All in all it was a complete rip-off. A $150 AAA "Premier" roadside service would make a LOT more sense that throwing away $ on run-flat tires constructed with a too-soft compound.
Personally, I've begun buying 5 tires instead of four plus "replacement certificates." for AWD/4WD vehicles. And rotating them regularly. That way I don't throw away 3 perfectly good tires because of the loss of a 4th due to road hazard.
It's a product like slime has where you put in on any type of tire. Not sure how long it lasts. The link to product i posted looks to be made up of different compound vs slime's product which you pump in through. Don't know anyone who ever tried using it so can't say if it lasts life of tire.