I've been buying E20 and find if don't use the car for a few days the fuel gos down, id evaporation possible?

amazing if it does with it being a closed system? Maybe the resident "experts" can enlighten us.

Me too, I leave the keys on the table and when I get back home there is less in the tank than before. Haven't worked that out yet.

CAR + B.I.L. = Evap.

Two legged rats me thinks!

It's sometimes amazing how good the vapor containment is on locked gas tank caps. You should see the difference.

A few cryptic replies.

If it does evaporate, whereabouts would it escape?

The same way as any other Benzine. .

amazing if it does with it being a closed system? Maybe the resident "experts" can enlighten us.

If a fuel tank was a closed system, it would be impossible to pull fuel into the cylinders.

And yes it evaporates because it is alcohol.

A few cryptic replies.

If it does evaporate, whereabouts would it escape?

probably escapes into motorbikes.

If you Google: "vapour pressure alcohol vs petrol" you will find scientific papers that suggest evap losses are higher for Gasohol blends!

"Evaporation" sounds a nice way of putting it.

I believe supermarkets and others call it 'Shrinkage'.

It would take a mighty lot of evaporation to show on your fuel gauge.

amazing if it does with it being a closed system? Maybe the resident "experts" can enlighten us.

If a fuel tank was a closed system, it would be impossible to pull fuel into the cylinders.

And yes it evaporates because it is alcohol.

It is not a closed system as there is a vapor vent otherwise you can get vapor lock. I had a Porsche that would not start after I parked it. I opened the fuel tank cap and a loud hiss came from it and then it would start. Faulty vent in the fuel cap. Also you will find environmental studies on alcohol vaporization contamination being higher then just benzene.

if don't use the car for a few days the fuel gos down

Too vague to decide. "few days", "goes down".

It is known that ethanol fuel deteriorates over time by attracting water/vapor.

I read that such fuel should not stay in the tank for more than a month or so.

I use E20 regularly and do not see exceptional dwindling, just consumption (about 7.2l/100 km).

Have you checked for a fuel leak? It's more likely than evaporation.

Have you checked for a fuel leak? It's more likely than evaporation.

No, I wouldn't know where to start.

It isn't that a huge loss.