Correct tyre size on X3 3.0d?

[aaronc]

'56 plate X3 3.0d

Hi all

I seem to have different sizes front 245/50/18 and rear 255/45/18, does anyone know the BMW spec they were supplied with?

[richthedray]

Hi I have a 3.0d M sport X3 and had the same thing front tyres narrower but 5mm thicker than the rears, I purchased my car from a main dealer so I took it back there for an answer, they looked up the spec and it is correct to have different sizes on the car.
I hope this helps you.