Spec sheet tank capacity vs. maximum you've filled...

[F18RSC]

I once drove 30 miles on 000. It was during the fuel strikes a few years back when all the panic buying started.

I often find I put more in the tank then the spec sheet shows as the capacity.

[Artey]

VAG cars have some sort of buffer which can be activated during fueling up which adds 5-7 litres of additional capacity.

[Ozzie Osmond]

All that's happened is that by pressing on with filling after the pump has clicked off you end up filling the expansion tank as well as the fuel tank. Hence the apparent over-capacity.

Fuel underground at the petrol station is cold. Get it out and put it into your car on a hot day and it's still cold. As it warms up it expands and if you've filled the expansion tank your fuel will just overflow onto the road. Which is a bad thing.

Best to stop filling as soon as the pump clicks off. (Assuming it's not one of the stupid pumps which click off every few seconds.....)

[blueacid]

Ozzie Osmond said:

All that's happened is that by pressing on with filling after the pump has clicked off you end up filling the expansion tank as well as the fuel tank. Hence the apparent over-capacity.

Fuel underground at the petrol station is cold. Get it out and put it into your car on a hot day and it's still cold. As it warms up it expands and if you've filled the expansion tank your fuel will just overflow onto the road. Which is a bad thing.

Best to stop filling as soon as the pump clicks off. (Assuming it's not one of the stupid pumps which click off every few seconds.....)

On the flip side, if you know you're driving a long way immediately after filling up, fill it right to the brim

[briang9]

Artey said:

VAG cars have some sort of buffer which can be activated during fueling up which adds 5-7 litres of additional capacity.

how does that work?

[Krikkit]

Ozzie Osmond said:

Fuel underground at the petrol station is cold. Get it out and put it into your car on a hot day and it's still cold. As it warms up it expands and if you've filled the expansion tank your fuel will just overflow onto the road. Which is a bad thing.

Considering you get expansion of 0.01%/degrees C, that's a load of balls, and the ground temperatures actually follow the air temperatures quite closely in terms of fluctuation averaged over a day/month etc. The difference is nowhere near what you might expect.

Edited by Krikkit on Sunday 2nd August 00:09

[F18RSC]

Also depends if I am about to leave Europe and it's around 80p a litre!

[dcb]

anonymous said:

[redacted]

72 litres in a 70 litre tank. Computer had been saying zero miles
left for 30+ miles.

I was slipstreaming lorries along a Belgian motorway.

[battered]

briang9 said:

Artey said:

VAG cars have some sort of buffer which can be activated during fueling up which adds 5-7 litres of additional capacity.

how does that work?

Probably not a physical buffer but a fudge on the "distance remaining" so that when it gets to zero miles left you still have a few litres left. That way if you are a regular "run it to zero" man the car won't actually stop the instant the counter goes to zero.

We could do with a return to the 1980's Maestro that talked to you.
Click. Brrrr. Engine dies.
"What the f*?"
"Look, told you. What part of "Empty" don't you understand? What isn't clear about "zero miles remaining"? What is at all confusing about the message "Fuel level low, please fill immediately"? So I f*ing told you, knobhead. You chose to ignore me. This is what happens. Now suck it up and start walking. F*ing ignore me next time, tosser, see what happens." :-P

[daydotz]

Certainly with my A1 you can vent the tank & squeeze in a few litres into the expansion tank

[snoopy25]

daydotz said:

Certainly with my A1 you can vent the tank & squeeze in a few litres into the expansion tank

Most ive ever been able to get in my Megane Coupé is 58 litres when the tank holds 60 and that was with the petrol pump clicking every micro second

[Riley Blue]

battered said:

briang9 said:

Artey said:

VAG cars have some sort of buffer which can be activated during fueling up which adds 5-7 litres of additional capacity.

how does that work?

Probably not a physical buffer but a fudge on the "distance remaining" so that when it gets to zero miles left you still have a few litres left. That way if you are a regular "run it to zero" man the car won't actually stop the instant the counter goes to zero.

No, you can fill the expansion tank with petrol. Only to be advised when you're about to set off on a long run. The expansion tank is opened when you screw in the fuel cap however you can also do that when you're filling up so can get more petrol in. Have a look down your VAG car's filler neck.

[MJK 24]

I've managed to squeeze 99 litres in the Touareg which is supposed to have a 90 litre tank.

Even when the needle is fractionally above the bottom of the red, it'll splutter around right hand bends when super low.

[MissChief]

55 litre tank, 54.89 litres. I have a VAG car and I've never seen any way to vent the expansion tank?

[Dodsy]

I find the Jag fuel gauge and mileage remaining indicator is very accurate. Recently I stopped for fuel with the pointer on the stopper and mileage remaining showing 10. Got 84 litres into an 84.5 litre tank.

The Jag is unusual IME in that when the pump clicks off the tank it totally brimmed. If you try and get even a few ml of extra fuel in after the click it runs out of the filler.

The TVR on the other hand well who knows what is going on , if the gauge shows empty its just a reminder to fill up sometime in the next 100 miles and when the filler clicks off you can get a lot more in, but have to be careful not to overdo it or it just runs down the overflow to the front of the car and fills up the carbon cannister.

[battered]

Riley Blue said:

battered said:

briang9 said:

Artey said:

VAG cars have some sort of buffer which can be activated during fueling up which adds 5-7 litres of additional capacity.

how does that work?

Probably not a physical buffer but a fudge on the "distance remaining" so that when it gets to zero miles left you still have a few litres left. That way if you are a regular "run it to zero" man the car won't actually stop the instant the counter goes to zero.

No, you can fill the expansion tank with petrol. Only to be advised when you're about to set off on a long run. The expansion tank is opened when you screw in the fuel cap however you can also do that when you're filling up so can get more petrol in. Have a look down your VAG car's filler neck.

Oh right, I didn't realise they had a physical expansion tank. None of my cars have ever had this, but then I've never had VAG. Mine just has a filler neck and a headspace in the fuel tank, but what can you expect with 3rd world technology?

[kambites]

My best is 39 litres in my "32 litre" tank but that's slightly less impressive when you consider that the tank in later cars was switched to 36 litres but appears to be an identical part.

Others have apparently managed to get 45 litres into it which is nearly 50% over its stated capacity.

[f1nn]

I see the OP has an E90 BMW, as do I.

I regularly get 61, 61.25 litres in the tank when I fill it.

Also, when the range on the computer drops to "------" you still have at least another 25 miles, if you drive like a saint.

On a similar note, I hired a Transit van once, and coming off a motorway slip road the range dropped to zero, and about 300 yards later the Van stuttered, that was a close call.

[mattlad]

Ford Orion Ghia injection, fuel tank capacity 48 litres I used to put in 51 litres......

[750turbo]

briang9 said:

Artey said:

VAG cars have some sort of buffer which can be activated during fueling up which adds 5-7 litres of additional capacity.

how does that work?

Witchcraft!

Pretty sure he is wrong.