[SOLOMEK]

...an integral part of the stock suspension and must be installed to preserve the performance and dynamics of the vehicle as BMW intended.

Yes?

[BrettKA7]

Some BMW suspensions (IE base pre-LCI F30 suspension) are softened to allow for comfortable use of runflats, so the runflats can provide a sense of handling being "on rails" compared to non-runflat.

However, the BMW website appears to have RFT and non-RFT options for the 230i base, 230i M Sport, and M240i so if you have an M Sport or a base LCI, I'd say that claim is definitely false. If you have a pre-LCI base suspension then I think someone else may need to answer here.

[4Hockey4]

Odd, I was at BMW Richmond yesterday and the tech there said they were same (I have 16' 235i) and changing to PS4S would make huge difference and improve driving. Have the M performance model with exhaust etc.

[K8_M235i]

Don't listen to anyone recommending run flats.

[Maynard]

He is full of it, spouting generic sales literature that sounds like it was originally written for 'radial tuned suspensions' of the late 60's. 'Performance non-runflat tires' have been available standalone throughout the model's lifespan. It might be possible that his dealership will only replace original parts, as delivered, but that is doubtful; more likely it is a hard sell for those expensive and craptastic RFT's they have sitting about in piles.

[dradernh]

Originally Posted by Maynard

He is full of it, spouting generic sales literature that sounds like it was originally written for 'radial tuned suspensions' of the late 60's. ...more likely it is a hard sell for those expensive and craptastic RFT's they have sitting about in piles.

Thanks for a wonderful summary of OP's situation.