Hi all, Bit of a silly question, maybe, i have a 2014 A6 Ultra, around town i get between 25-32mpg max with the engine at correct temp. When it's cold the mpg is around 20-22. When i do the same journey in the evening around 23:00 hrs the mpg jumps all the way to 45-55 mpg. My driving style does not change, can any one shed some light on this? Again, i know it's a bit of a silly question but i've never owned an Audi before so this is new to me. I did own a diesel mondeo 2007 before this which did consistant mpg all the time but this is definitely not the case with my A6.