I know it's been discussed previously but would like to know others thoughts... Up until mid December my car was doing 38-39 mpg, only really being used at weekends, mostly round the doors and maybe 25% motorway/dual carriageway. After a change in job I now use it for the daily commute aswell, about 6.5 miles each way in traffic. By the time I get to work the car has hardly warmed up in the cold mornings and on the way home it just gets up to temp. The mpg has dropped to 31.9 despite my best efforts. I was a bit concerned until I had a 330i courtesy car for a couple of days. Same journey,same conditions etc 22.6 mpg.