Actual fuel tank capacity

Jobbo

New Member
Joined
May 2, 2023
Messages
24
Reaction score
1
Points
3
Location
UK
I collected my new S6 Avant a couple of weeks ago and am generally very happy with it. I do a lot of miles so I dismissed the 5-series and E-class on the basis that they only have 66l fuel tanks; the C8 with the larger tank has 73l and that's standard on the S6 - coming from a C7 Allroad with ~75l tank and prior to that a Merc CLS with an 82l tank, I appreciate the near-700 mile range at ~40mpg because I only have to fill up once a week.

Yesterday I filled up my new S6 for the second time and this time I ran it down to zero range, (where it flashes up the warning message to fill immediately) then filled up at the next place about half a mile further. I only got 66.29l in the tank. That's nearly 10% less than the quoted capacity; yes, I know Audi state 'approx' but it's more approximate to the 63l standard tank capacity than the increased 73l tank.

Has anyone else found their tank does not hold as much as they expected? I would expect only 2-3 litres left in it when the range is at zero, so either the tank is very much more approximate than I thought, or the wrong tank is fitted to my car, or the calibration of the range way out and there was actually 7l or so left in the tank? Since I've been getting an easy 45-50mpg sitting on the motorway that's 70-75 miles of range I'm missing out on.
 
Think it is most likely the range calculation that is overly cautious. Imagine the fuss if it told drivers there was 5 miles left and it ran out. Also in Germany it is technically illegal to run out of fuel so they need to be cautious. The distance remaining calculation is based on a number of factors including current and longer term fuel consumption which is why the range can go up and down almost on a daily basis.
 
7l left is overly cautious though; when I ran my C7 Allroad down to 0 miles remaining, there was about 2-3l left based on the quoted capacity. What's the point in having a whole extra gallon of capacity which isn't usable?
 
this is pretty typical on all diesel vehicles. The consequences of running dry is serious and as already mentioned running out of fuel in some European countries could get you a hefty fine. It’s not fun trying to get a car started again after running the fuel lines and pump dry…
 
I’m aware that it’s bad to run dry. That’s not really my question - maybe I should rephrase it: how much has anyone with the standard capacity C8 fuel tank put in when the range indicator reads zero? I have a suspicion my car may have been built with the smaller tank rather than the 73l tank it should have…
 
I’m aware that it’s bad to run dry. That’s not really my question - maybe I should rephrase it: how much has anyone with the standard capacity C8 fuel tank put in when the range indicator reads zero? I have a suspicion my car may have been built with the smaller tank rather than the 73l tank it should have…
Have you checked on myAudi app? this would tell if it has been an option chosen or not.

If you managed to get 66 litres of fuel in your previous fuel run, I’d wager a good bet you have the larger 73 litre tank capacity.

Unfortunately the range difference is nearly unnoticeable. This was the case on my Passat, I noticed maybe 75-115 miles more depending on the driving conditions at the time. Bear in mind 10 litres increase is around 2 or so gallons of fuel more than standard. If you average 40-50mpg that’s approximately around 100 mile extra range difference to the 63 litre.

with regards to the trip computer showing 0 mile range but has a gallon of fuel left this is completely normal in VW group diesel vehicles. And yes it does make the mpg look worse than it probably truly is but the consequences of running out of fuel are far worse. So it’s not a bad trade off in a squeaky bum situation.
 

Attachments

  • IMG_7223.png
    IMG_7223.png
    213.9 KB · Views: 56
It’s a bit of a shock after having a C7 A6 which you could run down to 0 miles’ remaining range and have about 2-3l left against the quoted tank capacity. The 73l tank is already a 2l reduction from the C7; losing a further 4-5l because you can’t use the last 7l is a bit irritating and will probably lead to me running out at some point when I try to guess how much is really left - counter productive!
 
Have you checked on myAudi app? this would tell if it has been an option chosen or not.
I have had a look at this - I assumed it would just list what the standard spec for the car is rather than being specific to my car, but actually I think the data is a bit better than that. It does say 73l tank. Also answers another query I had because my headlights and taillights don't look like most C8 A6s I've seen; it is fitted with LED lights, not Matrix LED, which I guess are the most basic lights. Actually I quite like not having the scrolling indicators and the claw-like rear light graphics, and I've never found matrix lights to work particularly well on the roads I use so I'm absolutely fine with that. It is an indication that Audi are reducing standard specs though; this is on an April 2023 build S6 Avant black edition, where there was no option to choose any other headlights. Haven't spotted anything else missing...
 
Just looking at the Audi website, with the exception of the RS6, it looks as if Audi have dropped Matrix LED lights from all parts of the range. Matrix used to be standard on the S-Line and then I think the Vorsprung got the HD Matrix. All version now seem to have the basic LED headlights.
 
A lot of cars being built between 2021-2022 were effected by component shortages. In fact my vehicle had features included on the MY22- even though mine was a MY21 build (December).

My whole entire spec was revised several times during build. I actually had the matrix headlights included on my Black edition as standard where before it was an option, which I had not selected.

I never got the tyre pressure monitoring system as promised neither the wireless charging (centre console). Apparently it was an option which was called tech-plus pack, which is no longer mentioned anywhere in the specification/equipment options, yet I’ve seen MY22 models with the wireless charging in the centre console…Go figure.

Check in with a preferred dealership to verify your spec. The sales chap I spoke with recently advised me there are still some outstanding campaigns on new vehicles to have certain features enabled or retrofitted that were not available at the time.
 
I am fairly sure I don't have wireless charging, though since I had that on my C7 and it just toasted the phone without actually putting enough charge in to keep it topped up anyway, I am glad not to have it now. There's definitely a tyre pressure monitoring option in the MMI in mine but I don't think it's the full sensor-based TPMS, just the traditional wheel speed difference detection.

Will have to check with the dealer; thanks for the suggestion. I don't actually miss the things which might be considered missing at all anyway, I'm pleased to say.
 
I am fairly sure I don't have wireless charging, though since I had that on my C7 and it just toasted the phone without actually putting enough charge in to keep it topped up anyway, I am glad not to have it now. There's definitely a tyre pressure monitoring option in the MMI in mine but I don't think it's the full sensor-based TPMS, just the traditional wheel speed difference detection.

Will have to check with the dealer; thanks for the suggestion. I don't actually miss the things which might be considered missing at all anyway, I'm pleased to say.
Looks like wireless charging has gone from the spec of the A6, used to be part of the Tech Pack in pre 2021 cars. With TPMS if you only have the option to set the current pressures in the MMI without actual pressures displaying then you have the ABS sensor based TPMS rather than the valve sensors based system. I think in the UK only the RS6 gets the valve based system
 
Sounds consistent. I thought the specs would be very easy to check since there are so few options available to choose now; with luck this thread may be useful to anyone ordering a new C8.
The lack of TPMS sensors is great from my point of view; far easier to find a second set of alloys for winter tyres. I think the 20" C7 alloys from my Allroad that I have in the garage will fit; the dimensions are identical including the tyre size. Wondering how wrong it'll look on previous gen wheels.