I started to read, but stopped when the article included a glaring error.
unlike water, petrol has no surface tension and will leak through the tiniest of gaps
Err no, petrol has a surface tension of about 0.29*10^-6 kN/cm which is a lot less than water, but any liquid has one. Otherwise, give it a shake and it would be as good as a gas!
Article might be recent on that web site, but I'm pretty sure I've seen it before - a while back so getting hold of unadulterated petrol may be harder.
If you fancy being a bit dangerous... Buy a Mr Funnel to separate water from petrol. Then dump a large amount of water into adulterated petrol. The ethanol will dissolve preferentially in the water, and you then remove the water with your Mr Funnel.
I do have to say though, you are mucking about with a rather dangerous substance and I cannot take responsibility for anyone maiming or killing themselves!
