Not sure about the insurance side, but I can't imagine ditching the runflats would be a problem as long as the correct size, weight and speed rating. To be sure, phone your insurer and ask.

Runflats do create a firmer ride but the cars are ultimately designed for them and it does make life easier if you get a puncture. Otherwise you'll have to buy an inflation kit and tubes of gunk which won't get you out of a blowout. BMW don't supply anything in the boot to change a wheel either.

Why would you need to buy an inflation kit and tubes of gunk?. Simply buy a spare wheel kit, plenty of places do them online. Just looked at the wheel shop, £185 for complete kit, space saver with tyre, jack and wheel brace. That is for the F10/11 5 Series (2010-2017), kit for younger model is the same price, but price for an older one is £30 less.

Find out how much dearer the runflats are than a standard tyre of the same size (x 4)

Personally, I'd get rid of them (assuming insurer happy enough). Cheaper to buy, quieter and better ride.

<< Simply buy a spare wheel kit, plenty of places do them online. Just looked at the wheel shop, £185 for complete kit, space saver with tyre, jack and wheel brace. >>

Always assuming the car has been designed with space to keep a spare wheel ... I would prefer not to have one loose, or even tethered, in the boot.

I'm fairly sure that not all 5 Series in this country (never mind others) had run flats, so I think it would be fairly safe to assume there is a spare wheel well.

<< I'm fairly sure that not all 5 Series in this country (never mind others) had run flats, so I think it would be fairly safe to assume there is a spare wheel well.>>

You are probably right, BBD. But I thought much of the rationale behind runflats was the removal of a space-wasting wheel well ?

I think it is more the weight of spare wheel, tyre, jack, brace, etc. Partly because of the rational that every little bit of weight saved is a good thing, but probably more because not providing them saves the company money!. I have no doubt that there are markets where run flat tyres are not really a thing and tins of gunk would be no use (Russia for example). There has to be a floor pressing with a spare wheel well for these markets and probably not much economic case for making another floor pressing without for markets using run flats

Thanks everyone for your comments,the ride on the car seems to be ok so will probably replace with run flats.Is there any need to replace with Premium tyres such as Michelin.On my previous car I replaced all four with GT Radials which were very good...