Anyone looking to change their tyres on their 19's I would strongly recommend taking a look at a set of the Pirelli PZero Runflats. I recently fitted a set which were given to me by a mate at Pirelli - replacing the std Continental UHP's and I have to say they are a revelation! Better ride, more steering feel, quieter, much improved handling, the beast really hunkers down and rips into the curves - also i think they are slightly better on economy, being a C rating v's the Conti's F .
When I test drove the x5 before purchasing, the demo car had 20" wheels with bridgestone duellers and it felt very dynamic and well dialled in. I was always a little disappointed that mine on the 19's never felt quite as well sorted (I took the 19 option owing to the terrble roads in Sheffield) , but with theses PZero's I now feel I have best of both worlds
