True fuel consumption

[alogbe]

I have serious doubts about the fuel consumption reported by Audi's on-board computer.

I had an A4 1.9TDI for many years which showed consumption better by around 8-9% than the real consumption measured by reference to actual quantities of fuel purchased.

Now I have an A6 2.7TDI and the same thing is happening: the computer display says I am using about 6.6 litres per 100 km (about 43 mpg), but the reality is about 7.4 litres per 100 km (about 38 mpg).

Has anyone else compared the computer display with actual measured consumption?

[buster]

I have serious doubts about the fuel consumption reported by Audi's on-board computer.

I had an A4 1.9TDI for many years which showed consumption better by around 8-9% than the real consumption measured by reference to actual quantities of fuel purchased.

Now I have an A6 2.7TDI and the same thing is happening: the computer display says I am using about 6.6 litres per 100 km (about 43 mpg), but the reality is about 7.4 litres per 100 km (about 38 mpg).

Has anyone else compared the computer display with actual measured consumption?

Mine is usually quite accurate, except when on LPG.

If mainly on long trips and it says 26, then it is usually between 25.5 and 26. If I am doing a lot of arond town driving it could say 19mpg, but then it will between 18.5 and 19.5.

If on LPG it does 19-20 whatever the DIS says.

[Col]

If you have got vagcom, you can calibrate the fuel competer to be spot on.

It is trial and error thing though and you can obviously only make the adjustment once per tank as you need to benchmark the computer vs actual (pen, paper & calculator).