smaller rear tyres?
 

Firstly let me apologise this question is actually for my wifes bmw 320d m sport e90 and not my scoob. At the minute it is running 225 40 r18 on the front and 235 35 r18 on the rear run flats. It requires the rear tyres replacing but at £250 a corner im after a cheaper option.
Does anybody see a problem with running the 225s on the rear as well. As these are only £160 each.
Or can anybody record any other options???



only £160 each.

They are normally staggered width wheels on the BMW, hence the staggered width tyres. If you use the narrower tyres on the rear there will be a stretch on them. Im unsure if this will affect anything though but thats the reason for the staggered tyres.