Now the warmer weather's arrived and my 6 month old CLS has 6K on it, the mpg has become nothing short of amazing! Even shortish trips of 20 miles are returning over 50 mpg and yesterday I did a 180 mile return trip to Kegworth and even with plenty of stop start on the M1 and struggling to keep close enough to the legal limits when I ran late, the door to door OBC mpg was 59 !!!! I've previously calibrated the OBC by brim to brims so I know it's with 2-3 %. In a world of disgruntled low mpg owners, all credit to Merc and the CLS250!