Demonstrated pretty well today that temp has a huge effect on mpg. Picked the missus up from work, went to the Metrocentre, then her mams and then home, 37 mile round trip, was caning the car up 2 long sliproads (one onto the A1, one onto the A19), each pretty steep and about 3/4 of a mile long each and maintaining 80-85 on the dual carriageway sections, with the aircon on all the way. Result was an indicated 55mpg for the trip on what has been the hottest day of the year so far (21C). A few weeks ago, doing the same on a miserable 12C day with no aircon would have just brushed 50mpg. That's not down to running in. Up to about 7700 miles.