You will never get the fuel consumption indicated by the on board computer. It consistently understates consumption by more than 1litre/100km (or 11.4%) - this had been verified by MBSA. This soft ware problem, as well as the "stop/start" function that only works 50% of the time, had been reported nearly 2 years ago to them via the respective dealers. 6 Months ago they confirmed that a soft ware patch will be developed to fix the wrong calculation. After numerous follow-up -mails, Alli's feedback is now that their R&D advice "that the current calculation of average fuel consumption is within the design tolerances of the ML"...what a big tolerance for a product range costing nearly R1m and claimed to be "the Best or Nothing". I have to accept that the ad hoc working of the "stop/start" function is also "within the design tolerance of the ML".