What size tank do I have?

[reggieroo]

How to I know what size tank I have, it's one in the spare wheel well in an Audi S6 Avant. Some days I get 37 litres in, other days 45. Sometimes it doesn't click off though so I stop at 45 max. The last time it clicked off was 42 litres & that was on a warm day. These figures are alway from empty. Would it be about a 50 litre?

[john_d]

should tell you on it.

[reggieroo]

When I looked the other day I couldn't find it but I just went & took off the top cover of the tank. Found the info & it is a 60L tank, & says fill to 80% max capacity. Funny how I can only ever get between 37-45L in. I should be able to get 48L if my math is right.

[john_d]

48 is correct, remember that the tank will never be completly empty when you fill it, there will always be some left as it will switch to petrol when the pressure drops to a certain level.

[mat_fenwick]

there will always be some left as it will switch to petrol when the pressure drops to a certain level.

...and the point at which the pressure drop triggers the switch to petrol will depend on the engine load, and hence gas demand, at the time.

[binder4]

I've run mine bone dry once, its supposed to be a 60 litre tank, it took 57 litres. Was never sure if the size stated here (In Australia) is what it will fill to, or what the actual size of the tank is. I
figure it must be what it will fill to after that, otherwise It should not have taken more than about 50 litres.