Hi, My 2000 Octavia 1.9TDi has done just over 160k miles and over the last 4-6 weeks the consumption seems to have tailed off. I normally get approx 53 miles/gallon but I am currently getting 44 mpg. Is this what I should expect as the mileage goes up or is it likely to be the temperature / MAF controllers ? Should I get it checked out ? I'd appreciate any guidance going. Thanks, Irene

Could just be the temperature.

One thing that can go from about 80k miles upwards is the spray pattern on the injectors, which can lead to a lot of fuel on the bores of the cylinder rather than as vapour.

MAF is an option, especially if you've not had a new one in 160k miles.

Have you put a new air filter in in the last 15k miles as if not this can also help a lot too.

If you get it scanned it could be the engine temperature sensor as the wrong values with affect the fueling. and as above MAF could be on its way out, again a scan should help

This time of year, my thoughts would normally turn to the car running on "Winter diesel".

However, mine just had a new cambelt, and the garage retimed the fuelling electronically. The result has been better economy on my regular commute (owned car over 3 years, traffic not changed much in that time, using same make of tyres). So if you've just had a new cambelt fitted, maybe the fuel timing is out.