Diesels are not just about the economy....because of the torque they have and the fact it is produced so low down in the rev range they suit the X5 much better. Yes they rattle a bit on start up and don't sound as good high up the rev range but as an everyday car to drive they are far,far superior. Once you've had a diesel it seems very antequated having to really rev a car to get the performance out of it.

The only BMW petrol engined cars that are superior are the M/// cars. There is a case for the 335i but the 335d is a fantastic car too.