My economy is getting worse! ?
Don't understand what's happened over the past couple of weeks. On my usual 30 mile commute to work in my 170TDi I could always get 48mpg on the DIS, however, with exactly the same driving over the past two weeks I simply cannot get above about 42 to 43? What's going on?!! The only thing I can think of is that I usally fill up with Shell Dieselt Extra but the other week I topped it back up to full with about 4 gallons of Sainsburys - could this have contaminated the tank some how????