I had a 318, underpowered and drank fuel like a fish does water!

Now got a 320d and its brilliant on fuel. Most of my driving is short trips, around town etc and it does high 40s to the gallon, that's me putting my foot down a lot. I have a decat and front mount on (still not mapped) One thing to sort out straight away are the swirl flaps. Get them blanked if they haven't been done already.