my fuel consumption has dramatically improved due to the following:
1. i have just discovered my tyre gauge was broken, so tyres way too low.
2. i have developed a new style of driving. my other car is a sporty manual, and i was carrying over this baggage to the new car. i have discovered that the Merc doesn't like any of my driving input preferring just to roll along at it's own pace. so now i hardly touch the accelerator and it wafts along very happily. flooring it makes no difference at all.
3. my original assumption of comsumption was based partly on monetary value of fuel i was putting in. ie LRP which is more expensive than unleaded. i have since found out i can use unleaded so the cost has reduced too.
i might try one of these Hiclone things too in the near future.