996 petrol tank expanding

[nickster]

I have a black car,so admit it may suffer in the heat a bit more than others - but wondered if anyone else had any experiences with petrol spewing out once you've
filled up.On a hot day a few weeks back,I lost about 4 litres.I remember this happening on a 1967 911 once,on a hot day years ago.Is this some sort of design feature?Does everyone just dare fill up 2 thirds if the weathers good.

cheers

[clubsport]

cant afford to fill my 92 litre tank up that much...

Sorry never heard anything like this,particularly as 996 is sold in warmer climes than a decent UK summer,4 litres also sounds a lot to me that is close to a gallon in old money.

>> Edited by clubsport on Wednesday 20th August 14:29

[philly]

This might sound a bit pedantic, but if the tank expands wouldn't you be able to get more fuel in?

[eddiethedog]

I know it's not quite the same topic, but back in the 90's in what was the Group C World Championship the cars would be filled to the brim in cool garages then driven round to the grid where they were then topped up. At hot tracks (Jerez etc), the tanks would expand to a scary degree....Brundle used to say that he could sometimes hear the fuel boiling behind him when sitting on the grid with the engine off in the Jaguar...

[GLpinxit]

Probably caused by the fact that the fuel is stored in underground tanks where the temperature is likely to have been around 10 degrees and will have warmed up to air temperature (30+?) once transferred to your car. Petrol has a fairly high coefficient of thermal expansion (ie it expands quite a lot with temperature rise) so if you didn't drive very far before stopping then it wouldn't be unusual to lose some as it warmed.

Not unusual and a source of constant irritation to garage owners. In summer they buy a measured volume of fuel from the tanker so it is at air temperature, it contracts in the ground and is measured by the pump as delivered to your car so they lose money. By contrast the opposite happens in the winter but the temperature difference may not be as great.