7A cars - how many miles or kms per tank

[cgharibo]

Just curious how many miles the 7A car owners are getting out of a tank.

I have a 1991 7A and I average about 370 miles per tank.

[quattrodave]

Been a while since I had one but in the UK I used to get around 21 miles to a UK gallon of petrol on short runs to and from work ( 5 miles each way), I recall the tank was about 15.5 gallons capacity (70 litres) so that makes 15.5 x 21 = 310 miles, on a longer run it would do about 28 so that would be around 430 miles to a tank full.

This was a 90 quattro not a coupe.

[John.]

I average about 370 miles per tank.

That sounds ok, not sure if your US specification car differs to Euro spec. cars regards fuelling?

[steve briance]

My cq20v never gets a full tank as I can't bear the sight of how much it costs. When I drive to work it is 10miles each way, mix of country road, short dual carriage way and usually a bit of a queue. Driving sensibly I get around 26-27mpg. On a good long run up a motorway driven at a steady pace it can get 31-32mpg but that is just 'driving' and not enjoying the engine. Driven for fun over a country road it drops to low 20s.

I find that how you drive in the warm up phase has a massive impact on mpg, makes sense really - pressing on while the ecu enriches mixture.

[Mikes2]

Mines a saloon with a slightly smaller tank but I usually get around 450 miles. I've seen 480 a few times.

[Bowie69]

On a 63l fill (when the light comes on) I get about 320 miles per tank on normal driving, but then I do rag it most of the time

Longer runs, up to 380, but never got over 400, always too impatient.

[Lago Blue]

If one can create easily reproducible conditions, one can then more easily compare to your own results in the future.

For example, if you can drive steady-state for some known good distance (better yet, reverse course at half-way to negate a head or tail-wind), and having carefully filled-up before and after, one can then get a pretty accurate mileage number with reduced variables having influenced it.

While even a more basic fuel consumption log, kept for every fill-up might help one catch some gross change such as a fuel leak, a more detailed approach done periodically, can help one evaluate possible smaller changes or particularly mods that may influence mileage less obviously.

If a Coupe tank capacity is 18.5 US gal., then using my results below, and just driving further at that speed, I'd theoretically be able to get 645 miles / tank.

https://www.audiworld.com/forums/aud...-test-2128179/

[quattrodave]

For comparision best we ever got from our B3 10v coupe quattro pre cat convertor model in UK (very early example registered November 1988 in UK) was 33 miles to the UK gallon on a long run from Yorkshire to Cornwall, you could just about risk about 460 miles between fill ups on a long motorway run cruising between 70 and 80 with occasional blasts up to 90+ for overtakes (oh for the days before cameras I remember holding just short of 130mph for about 10 miles on the M5 chasing down a sierra 4x4 that overtook me, the oil temp gauge rose to 130 if I recall correctly) our 1991 20v 90 quattro was much thirstier on same run best I ever recorded was 30 to the gallon and that was after I removed the cat converter which obviously improved things slightly (legal on pre 93 cars in UK)

[Lago Blue]

Depending on exactly which model and how one expresses mileage, there are a surprising number of variables that may be at play here.

I do keep seeing that 70 liter number for tank capacity of both the 20v sedan and coupe, although i don't have an coupe owners manual handy to check.

Some possible variables:

- Imperial vs US gallons if you are saying mpg, vs miles per tank;

- Premium vs Regular fuel (two separate ignition maps);

- Windows open vs closed;

- A/C on vs off;

- Does a California car with EGR get different results? Perhaps only if the EGR system is invoked during more variable driving?

- Early vs late ECU;

- Is your O2 sensor getting tired and not cycling well?

- Original injectors or which?

- Winter vs summer?

- Coupe vs sedan: they differ in weight, overall gear-ratio and perhaps even Cd (also consider belly-pan on or off). The weight won't make any difference for constant steady state driving, but certainly will for when it is not.

I'm curious if you folks who have answered are either using a calculation to get either MPG or miles per tank, or the read-out from the trip-computer display?
Of course I never ran my tank dry to see if I could actually get that far, but I've re-confirmed those numbers enough times to know there no fluke. But then, my intake and exhaust are not quite stock either.

https://www.audiworld.com/forums/aud...check-2814421/

This discussion (below) was about the 2.8 12v V6, but certainly some of it applies to 7A's as well:

https://www.audiworld.com/forums/12v...leage-2805078/

[Mikes2]

I just go with miles per tank. Once the light comes on it usually takes 60-62 or so litres to fill it ( it's a 68 litre ski-hatch tank) which is 13 gallons over here. Best I've seen was 37mpg. I don't use the computer as I'm on Bosch injectors so it's never accurate.

[Audicted]

I have a 1991 US 7A Coupe Quattro. On daily round town driving I get about 280 miles between fill ups. When I do long trips I can get upwards of 370 per tank. Once when I was feeling particularly adventurous I got 405 miles before I relented and pulled into a service station on the CT Turnpike. My only modification to the engine is the 034 injectors. According to the US manual the fuel capacity is 18.5 gals/70 Litres. Chris, if you have the Bentley paper manual for the Coupe/80/90 there is an owners' manual in there. It appears right after repair group 97, a little more than halfway through the book.

[quattrodave]

No fuel computer or air con on either of our cars back in the day (1988 B3 coupe quattro 10v and 1991 B3 90 quattro 20v), these things were costly options on the UK spec cars back then, both fitted with undertrays, 20v had cat removed which did improve fuel consumption by around 2 miles per gallon average, it was also a later cast manifold car not the tubuler one so down on power.

Every car is different as Lago Blue says there are so many variables but compared to modern cars these things drink a lot more fuel. My Ur Quattro did around 17 to the UK gallon around town on work (5 mile there/back) runs, improving to around 28 to the gallon on a longer (Bradford to Cornwall) run.

Standard tanks in the UK were definitely 70 litre or 15.5 UK gallons on both cars, Ur had a 20 UK gallon tank somewhat costly to fill when it was almost empty and think of the extra weight yet another factor.

[Obli]

Sorry to reply to such an old thread but I wanted to add my contribution.

From memory, I used to get around 450 miles on a tank, driving B roads to work. The best I managed was 520 miles on a tank in my 90 20v, years ago. This was with a couple of passengers and a constant ~70mph. I understand the 90 has a lower drag coefficient compared with the Coupe. 90 is also lighter, mine even more so being a fwd and poverty spec. Mine has no cat. I wonder how the aluminium spoiler affects aero at speed... mine has the spoiler.

BTW, I believe the Coupe 20v has a 70L tank and the 90 20v a 68L. Mines definitely 68L.

[K Simmonds]

520 miles on a tank is pretty impressive, you must have been on a long motorway run and have a very light right foot, I guess the superior aerodynamics of the 90 as well a little less weight helped.

Best I ever got in my FWD NG (10V) Coupe was 460 miles, that was on a run up to Scotland so constant motorway at between 70 and 80 MPH and I was trying to drive as economically as possible.

[Obli]

Ah but the drive to Scotland is uphill, right?

Think I was running with Shell Optimax at the time which was definitely more economical. The 520 miles would have been until empty, based on say ~40 miles left to empty when the fuel warning comes on.

Could always be my memory playing tricks on me!