Fred - how are you so sure about the 9 litres remaining when the re-fuel warning comes on?

 

so it says in the manual
in my language on page 20.

 

I have the same A5 SB 2.0, and if the fuel warning "rings" the rest-over range is between 50 and 60km. Once i go to the limit, and drove to 0 km. At the Gas station i fill in 59 litres. With a tank of 64 litres i had olmost 5 litres left.
So I think you could go 100km with the rest of fuel.

 

exactly, but the DIS should say 100 km as well

 

Perhaps it is to encourage owners to re-fuel sufficiently before the tank goes dry, so that it prevents sludge being drawn into the fuel system?

I think I'm happier knowing that when the DIS reads 0 miles range I have some 'emergency' reserve left. It's a personal thing, and different people are bound to view it in different ways. I'm betting that some folk drive until the DIS reads 0 miles quite regularly :no:, and for them the extra 5 litres will save them from fuel blockages.

 

I've quite often run down to the DIS saying 0 miles left, and have even driven about 10 miles with it saying 0 with no problem. I've never managed to get more than 59litres in on a refil either. Don't want to absolutely run dry, so tend to go with what the DIS says, in the knowledge that I've actually got enough to get me to a petrol station when the DIS says I've run out.

 

I had 20km left in mine on Sunday (FD had the car all week - never looks at the petrol gauge!) and it took 59 litres.. So it had 5 litres left and in theory a maximum of 50km in city traffic - therefore if I was brave enough to let it get to 0Km, I might get 30km.. However, I suspect that the true limit is that the car has 3 litres left allowing for 1 litre in the fuel system and one litre of non-combustible rubbish at the bottom of the tank.. In other words, I suspect that she would have conked out in another 10kms...

Personally, I think it is a bad idea to let the tank get this low...

 

Personally, I think it is a bad idea to let the tank get this low...

+1

 

thank you all for your answers.
but don't you think the car should tell you what the actual situation is ??
"having some emergency liters left" sounds nice, but how many are they ??
the fuel-consumption should show a correct value, so should the spedometer, the engine-temp.gauge, the oil-temp., etc.etc.
why not the fuel-system ??
it is not my intention to run the tank almost dry every time.
I just want to know what's happening below the back-seat

 

Well I can certainly understand your point Fred. In most areas I'm very much the same (for example I'm pleased the speedometer accuracy in this car is far better than ALL my previous ones - I guess it has to be more accurate as it has links with the sat nav etc - my previous cars were all optimistic by about 2-3mph).
My opinion above was based on my 'guess' about Audi (and probably other manufacturers) 'babysitting' most drivers who perhaps don't have the technical understanding and precision of some of us here (the forum), and would be more likely to run the car to 0 miles frequently - then if 0 was really zero they would suck up s**t from the tank every time.
Like I said before, folks opinion on this is likely to be very personal, and I can understand your desire for precision completely. :thumbsup:

 

thanks Dan, appreciated
my car is 2 km's "fast" at 80 km/h and 3 km's at 120 km/h
I think they have to make it like that, in order to stay away from complaints, in terms of speeding tickets.
in order to tackle the left-over milage, I will begin with a precise check and possible correction of the fuel-comsumption.
so far I only checked it roughly
we'll what comes out of this

 

It's law in the UK. It either has to be correct (unlikely unless you have it regularly calibrated), or reading under by a maximum of 10%. Note tyre wear and pressures will also impact the readings.

 

I look forward to your results Fred.

 

1st result:
distance driven, since last fuel: 534,4 km = 332 miles.
fuel tanked: 48,38 ltr = 10,64 Gallon (imp) = 12,78 US gallon
calculated consumption: 11,05 km/l = 31,2 mpg (imp) = 26,0 mpg (US)
the DIS2 value was: 12,0 km/l = 33,9 mpg (imp) = 28,2 mpg (US)
this is a difference of 8% on the bad side.
next step is to correct this with Vag-Com and check again.
changed channel 03 of module 17 - Instruments from 100 to 108.

 

Be interesting to see your next values after the correction. Will be good if it works to correct the mpg in DIS. Will this solve the fuel remaining issue though Fred?

 

He Fred, I notice that I can never add more then 60 liters in my car. And this is only when I run it to BIS warning of 0 km's left.
Tried it today. How many liters do you think I have left. Guessing 5 since the tank can hold 65 liters.

I filled it up with 60 liters and I notice that when I am challenging myself not to speed or drive in sporty mode but drive in old granny mode that BIS tells me about 700 km's on a full tank. However this number is based on my driving style before the fill up.

The tank is full now and I start driving. First 300 km's nothing happens and BIS tells me still 700 km's left. Remember I am driving in granny mode. After 300 km my BIS finally is reducing the range left. So now I see the number 700 km going down to 0 km while emptying the tank.

Finally after about 900 km's BIS says 0 km.

Conclusion
In the beginning it is based on my sporty driving skill so it says 700 km's. It notices I am driving in granny mode and does not decrease the range since it knows that when I am driving like this continuously I will able to get 1000 km's.
However it seems to adjust itself since after a full tank of 60 liters (BIS back to 0) I have driven 900 actual km's. Averaging 15 km/l which is pretty damn nice for a tuned 2.0 tfsi with about 275 bhp (MTM baby) . People cannot believe this but are stunned when they see it However I still think it is strange it is not 1000 actual km's. It looks like the computer realises it makes a mistake and going down from 700 km's to 0 km's I corrects itself coming to the conclusion 1000 km's is to much and it should be 900 km's.

Finally very strange is that when running in granny mode I average out every trip above 16 km/l and in the end I still "only" get 15. I think same story and the computer corrects it.

Long story, hope you get it.

 

@shardphoenix;
I understand what you are saying.
when I have a full tank, my DIS says 740 km.
I don't know how it reduces over the distance.
but when the fuel-warning comes on, there should be 9 ltrs. left.
with an average consumption of 12 km/l there should be about 100 km left in the DIS. but it is only about 70.
now the first thing, I am working on here is to get the actual consumtion corrected, so that the DIS has the same consumption as the actual cons.
the fuel cons. you mention, is that according the DIS ??
or is that calculated from milage and fuel tanked ??

 

@Fred
My actual usage in granny mode is 900 for 60 liters. So when BIS says 0 I fill it up and then I can get 900 actual km's before BIS says 0 again.
So averaging 15km/l.

Strangle knowing that BIS average usage indicator never comes below 16km/l at the end of every trip. My average per trip is always 16km/l in granny mode. I guess I can say BIS is 1km/l off!

 

I would say that something is wrong somewhere.
the average fuelcons. stated by Audi is 6,5 ltr / 100 km, that would be 15,38 km / ltr.
i.e. for a 155 kw, manual, FWD
this value is achieved under laboratory conditions, on a dynamometer.

and you are doing 15 km / ltr.
there are numerous discussion about the overrated fuel cons. figures of Audi, and others for that matter.
I hope you are aware of the fact that for the official fuelcons. tests, the accelleration from 0 to 50 km/h is done in 26 sec !!!
I hope you are not driving like that

may be you should do an exact check of the fuelcons. and correct this according to the result, with Vag-Com.

 

now checking the behaviour of the left-over milage in DIS, after I corrected the fuel-cons. by 8%.
looked at left-over milage this morning, and it was counting down in steps of 10 km.
I'm sure it has started correctly.
not like others, driving 100 km before it would start going down.

 

@Fred
My home work route is 49.8km so let's say 50.
So 100km per day back and forth. When I drive granny mode I actually ca get 9 days to work out of my tank of 60L.
That is from 900 to 0 on BIS and stopping a few minutes at the gas station after BIS says 0.

I tested this by doing nothing else then home-work-home trips for 9 days and not a single other trip in those days (no social life during those days hehe).

Of course the milage number or the consumption number is could be of but that does not explain I actuallt can get 900 km's per tank to 0 on the BIS system...

I can check how much km's I can drive when BIS says 0 but I rather not try

End of march I tried breaking all my consumption records by shifting gears below 2000 rpm (indicator says to shift at around 1700) and I averaged out above 18km/l

If you look closely you see I drove 120km, have 900 left and averaged out at 18.1....oh lol Yes I did reset my km counter
I do however now that somewhere it drops faster so I reach about 900km in the end.

This is with Airco and music on (no battery saving settings or anything), normal Euro95.
Car is tuned by MTM and stock airfilter replacement by K&N.

 

@shardphoenix
well, if you want to check your fuel cons., and compare it with what the DIS is telling you, you should fill up the tank, reset BIS2, and the daytrip counter.
when the tank is almost empty, write down the numbers from DIS2 and the daytrip counter.
than you fill up the tank and make a note of the liters you have tanked.
now you have all the info to do the calculations.
with that you can check if the average cons. from the DIS2 is correct.

 

@Fred
What do you mean by resetting BIS2? You mean the red numbers indicating the BIS menu's?

I normally do reset the counter manually after a fill up o see how many km's I actually are getting 900 km from my e.g. 60 liters of petrol.

 

your car has 2 on-board computers, one is short term and shows its information in DIS with a "1". the second on-board computer is long term and show the info with "2".
you can reset either one or both when you go in to the MMI by pressing Car.
scroll down to instrument cluster and select it.
there you have the poissibility to reset your on-board computers.