On board computer Fuel economy calculation.

[sapstar]

Is the fuel economy calculation shown on an A6's on board computer accurate? It shows me 60 mpg for highway and around 35 mpg for city driving.
I made the trip calculator 0 when it showed me low fuel and then filled up around 62 litres of Diesel. Did 489 miles before it showed low fuel warning again. That comes to an average of 35mpg (i am assuming 1 gallon = 4.546 lts) in which I had around 350 highway miles. Seems to be highly inaccurate.

[gupsterg]

It shows me 60 mpg for highway and around 35 mpg for city driving.

Are you looking at instant MPG or average MPG in DIS?

[Rosscow]

I've found mine to be fairly inaccurate.

It was showing 47mpg average on a recent run to Heathrow and back (about 200 miles) but in reality it was actually 39.1mpg.

[sapstar]

Are you looking at instant MPG or average MPG in DIS?

I was looking at the mpg which is shown after completing a trip. I am assuming this mpg is for the complete trip from the time I start the engine to the time it is stopped.

[rafletcher]

You have two trip readings, and for each there is an average and instantaneous reading. Trip 1 is for your current journey only (if you stop foir less than half an hour it assumes one journey in two parts). Trip 2 is an accumulative one, for (I think) 99 hours before resetting. The button on the underside of the wiper stalk cycles through Trip1, Trip 2 and digital speedometer. The rocker on the end of the wiper stalks cycles through the various readings in the trip - average mpg (calculated every 30m I think), instantaneous mpg, elapsed time, average speed, etc.

[dcgecko2000]

" The button on the underside of the wiper stalk cycles through Trip1, Trip 2 and digital speedometer. "

I have a 2006 S-Line Avant and as far as I know thatbutton just cycles through the Trip 1 and Trip 2. Is the digital speedo something that can be turned on somehow?

[Rosscow]

I have a 2006 A6 Avant (SE) and I get the digital speedo exactly as Fletch describes it

[rafletcher]

" The button on the underside of the wiper stalk cycles through Trip1, Trip 2 and digital speedometer. "

I have a 2006 S-Line Avant and as far as I know thatbutton just cycles through the Trip 1 and Trip 2. Is the digital speedo something that can be turned on somehow?

Mine is also a 2006 S-Line (the Le Mans bit is just a variant) so I suggest you press one more time!

[vince31]

Back to the average fuel consumption reading, I've noticed that when I'm sat still in traffic then the avarage mpg reading dosent go down at all, even after being stationary for half an hour. Seems like being stationary dosent count, but in reality you are still using fuel and going nowhere. In my old BMW 520 the reading used to go slowly down when I was stopped. I have noticed the same amount of discrepancy as the original poster, on avarage about 5 mpg less.

[johnsimcox]

Back to the average fuel consumption reading, I've noticed that when I'm sat still in traffic then the avarage mpg reading dosent go down at all, even after being stationary for half an hour. Seems like being stationary dosent count, but in reality you are still using fuel and going nowhere. In my old BMW 520 the reading used to go slowly down when I was stopped. I have noticed the same amount of discrepancy as the original poster, on avarage about 5 mpg less.

Sounds to me that you are looking at the Trip 2 reading which is long term (ie does not reset after a two hour gap in a journey) as in my experience the mpg did drop when sitting in traffic (one of the reasons I like stop start in my new A6). It will take more than a short stop in traffic for this to be affected if it is based on many thousands of miles driving.