Please help,high fuel consumption need diagnostic

[cip82]

My car: Audi A6,C7,2.0 TDI ,177hp
Please help. I have high fuel consumption between 25-29 mpg in town. The best I had was 32mpg when bought the car from AUDI.
Also I have DPF regeneration every 60 miles.
Last november replaced injectors with reconditioned ones from Germany still same Mpg 25-27.
Start -stop doesnt work for about 8 months nobody seem to find any problem with it.
Also have some errors . Need someone who knows how to read data and interpret the numbers errors. Please someone who really knows what he is doing. I live near BRENT CROSS in London. I can come to you if its in 20-30 miles. Thank you waiting for reply.

[A6S]

These cars are big cars so town driving mpg is always poor.
They are only economical cruising at steady speeds.
Could be a number of things wrong with stop start.
First thing I would check is coolant temp sensor as this could have a massive effect on mpg and stop start. The dash could say one thing and the sensor could say another. Stop start won't work unless it's up to working temp.
Other things is tyre pressures or slightly seized brake calliper which is quite common for the rears. The little motors can burn out or the pads wasn't replaced properly following the correct procedure.
Is it a manual or auto?
In the manuals ss only kicks in with clutch down and and foot on the brake if I remember right. The micro switch on the clutch pedal can go as well so worth checking.
Hope this helps.

[cip82]

Thank you for your reply A6S. You put some light into my problems and confirmed what I read. I will definitely change the coolant temp.sensor its only a few pounds.Mine is manual so I know about the switch when I press the clutch but dont know how to check or if I go to a service I dont know if they will check properly or just want to take my money.Tyre pressure is checked properly and pads also. No braking without pressing the brake if that makes sense.
My consumption is quite high.Have a friend with S classe 3 litre diesel in town gets 29 mpg. Mine should get at least 32 mpg. I know Audi lying about consumption but mine it has something thats I need some to get me a good diagnostic. Thanks again.

[Silane]

How often do you do long drives? I only get low 30's mpg around town also. On the motorway I get mid 40's (120-140kmph). The quoted mpg figures are only possible cruising < 100kmph on the motorway. What size wheels do you have? I have 20"'s, this also knocks few MPG off. I don't think your consumption is too bad. I wouldn't be concerned unless it was equal bad on long motorway trips.

As for SS, there's a lot that can stop that from working all the time. Whenever I do short runs around town from cold it doesn't work. The engine has to be hot, the battery has to be fully charged, heated seats and AC need to be off, it probably won't work during a DPF regen which is often on these cars. If I go for a long drive, by the time I get back to town, stop start kicks in every time.

It sounds like your car is behaving very similar to mine, and I do a fault scan about once a week, and nothing ever shows up. This car was never built for short trips around town.