Sudden drop in mpg - 2.4 JTDm
The last couple of days my mpg figures have plummeted (156 2.4 JTDm). My weekday run to work is rather depressingly all dual carriageway with speed cameras - so I normally get really good efficiency on that run.
My average, according to the trip computer, was normally around 54mpg. Even in a hurry, i'd get 49mpg+. The last couple of days my figures for the same run have fallen to 25-29mpg. I'd hoped that it was just the trip computer playing up, but the fuel gauge is definitely falling more quickly than usual too over the last two days.
I've checked my tyre pressure, still using my normal fuel (BP diesel), no aircon running, everthing feels normal.
Any ideas what could cause this all of a sudden?