My BMW 520D sport has continental sport contact 2 tyres fitted which I am told are not run flats, is this so?

Question from colin, 25/10/2010 :I have just bought a bmw 520D sport I was told that it was fitted with run flat tyres but it has continental sport contact 2 tyres fitted which I am told are not run flats,is this so? They are 19" tyres and I would like to fit 18 " wheels and tyres is this possible? using the same size tyres front and rear.The existing 19" wheels have different size tyres front and rear.I would like to reduce the harsh ride provided by the continentals,what tyre would you suggest. Colin
Answer by rezulteo, 25/10/2010 :

Indeed, the ContiSportContact 2 does not exist in a run flat version. For your vehicle, there are "square" mounts in 18 inches (i.e. the same sized tyres at the front and the rear) such as the 245/40 R 18 93 Y. However, to confirm this dimension is compatible with your vehicle, please check your maintenance log.