Newbie Needs help with poor fuel economy

[Bagcharge]

Hi all I bought a 2008, A6 AVANT 2.0 140 TDi S line Automatic in Feb and got it re-mapped to around 170 as I was told that this would improve fuel economy as well as giving it a power increase. I do calculation on les and fuel used "not on the car readout" The car was only returning around 30 MPG or less around town and 37/8 on cruise at a steady 75 MPH on a run I did to Brighton. I have been told that this is poor, so have had it returned to the stock map setting and am going down to Donnington Park next weekend so will do a calculation for that.

My question is are here ant faults that might cause poor fuel economy but ill not register o he system?


Thanks in adance.

Bagchage

[NickPicks]

Thermostat, coolant temp sensor, air temp sensor.

Have you scanned it for fault codes? Use VCDS to see what the temperatures are in the engine management - if it thinks it's running colder than it is, then it'll inject more fuel to compensate. What does the dashboard say the engine temperature is? (It should be 90)

[neilos100]

Not sure thats too bad on an auto box...does make a big difference over manual.
Try doing a search on here and you may find results not too dissimilar to yours...

Neil

[Bagcharge]

Thermostat, coolant temp sensor, air temp sensor.

Have you scanned it for fault codes? Use VCDS to see what the temperatures are in the engine management - if it thinks it's running colder than it is, then it'll inject more fuel to compensate. What does the dashboard say the engine temperature is? (It should be 90)

Thanks Guys.

Had a diagnostic done this morning as the air con is also not working "Confirmed the Compressor is Goosed" But no other faults.