No he hasn't. Dunlops "bad", Goodyears "fine/good."

 

I settled on the Bridgestone RFTs on my 123d M-Sport, they were fine. The ride on that was much better than the g/f's 320d on Bridgesone RFTs.

 

I think there's a lot of bollocks spoken about run flats and ride quality - and tyres generally and ride quality for that matter.

I'd look at the rest of the suspension, from bushes, to springs, shocks and wheels before I worried about whether or not to use run flats.

 

My only long-term experience of run-flats was on a Mini with 17" wheels. There was pretty much zero compliance in the run-flat tyres' side-walls; take a look at the guys fitting tyres and it's clear the effort to get tyre over the bead in enormous.

But a suspension designed to accommodate the limited compliance of run-flat side-walls ought to be as good as a suspension designed for tyres with greater compliance - a friend's 5 Series SE with run-flats has a great ride.

I'm all for run-flats; a spare is arcane and space-savers are pretty much speed-limited to that of a punctured run-flat anyway. Who wants to piss about getting their hands dirty changing a wheel, as well as figuring out what to do with the 247 17" wheel when the space-saver's fitted...

Cost is the main objection to run-flats; there's still a hefty premium for them but my guess is as the technology is now pretty mature, the actual cost of manufacture is probably marginal over that of a non-run-flat tyre.

 

Part of the problem is that the suspension tends to be compromised for far too many wheel & tyre options, rather than particularly optimised tor the , er optimal size.

For example, the big 17" on a MINI are a possibly bit ridiculous cf. the sprung weight of the vehicle; those on the 5xx SE might just happen to represent the 'sweet spot' in the range. One tick box on the options list might have buggered up the whole car.