I recently rode a law enforcement vehicle equipped with run-flat inserts. The ride felt almost(?) as comfortable as a GT-R with stock run-flats. My understanding is that, unlike run-flat tires, run-flat inserts work with normal tires which have sidewalls much softer than those on the run-flat tires. Also, run-flat inserts are slightly smaller in diameter than the support rings that come with run-flat tires, so the ride quality is not heavily compromised.

The downside, like Reddit people have pointed out, could be that the run-flat insert will shred the tire if you keep driving after the tire has lost pressure:



Jokes aside, I have learned that these run-flat inserts are designed to keep going (slowly) after shredding the tire:


(Pictured: RunFlatInternational insert)


(Pictured: Bridgestone support ring system.)

I guess the run-flat inserts could be a major convenience in the event of a flat, especially when needed to get out of a bad area first or to drive into a hotel during holiday travel (when roadside assistance can take hours and if the area isn't safe for installing the spare). That way we don't need to remain in freezing cold to stay with the Evo.

Any thoughts? Are run-flat inserts a good idea? My thanks to you in advance.

 

On an Evo you'd burn up the driveline if you drove for very long/very fast on a single runflat. You aren't supposed to drive with uneven tread depth let alone how far that tire will sink if it's running on that support ring.