29th Aug 08 Hi,further to recent phone conversation have now covered 33000 miles over the last couple of years with a Green box in a Mercedes 220 cdi auto.The box is currently set just below the 10,the car is pretty nippy,and fuel computer is showing overall consumption at 51.2mpg.This is for mixed running,cold starts,town and dual carriageway driving.My wife has a similar spec.vehicle (no tuning box) is a gentler driver than me and consistently shows 5mpg higher consumption,e.g.46 mpg. all the best Steve