Has anyone had a successful positive indication of alcohol in Mogas using the recommended 10% addition of water in a tall tube. I have been told that all Tesco Mogas has alcohol in it but when I tested it, either the test is not sensitive enough, or there is insufficient alcohol yet for it to show using the above method.

I have been told that the test is not sensitive enough. I did try it specifically on some Tesco fuel and I could not tell. I avoid Supermarket fuel, and use my local garage which says its fuel is alcohol free.

Rod1

The PFA Devon Strut has reported acholol in Tesco fuel in the West Country. I have never found alcohol in fuel in Wales, bought at Tesco or other forecourts, using the standard test.

Does this allegedly substandard Tesco petrol meet British Standard [whatever it is] ?

Some U.S. states have some sort of directive going through to make petrol contain at least 7% ethanol or something like that...

Tesco fuel comes from a company called GreenEnergy - http://www.greenergy.com All the spec sheets are on there if you're having trouble sleeping

The current standard for petrol in this county is BS EN 228, which only permits a maximum of 5% bioethanol.

There's a good article about the various ethanol-petrol mixes in this month's Popular Flying magazine, including information on anti-knock additives etc.

The EU is planning a new standard for mogas with 10% ethanol, and there is talk of going to an 85% ethanol mix at some point, in fact according to the above website a 95% mix is already produced for buses ...

“new standard for mogas with 10% ethanol”

This statement is inaccurate. The new standard specifies 10% bio fuel. There is more than one bio fuel and it is only ethanol, which brakes the regulation.

Rod1

The August newsletter of the Devon Strut says:

A telephone survey of some of the major fuel suppliers on behalf of the Strut has confirmed that Tesco’s mogas in the southwest does contain ethanol but the pumps at Texaco, Jet and BP garages do not.

“new standard for mogas with 10% ethanol”

This statement is inaccurate. The new standard specifies 10% bio fuel. There is more than one bio fuel and it is only ethanol, which brakes the regulation.

Apologies Rod, I did not intend to mislead - see here for the press release which only referred to ethanol:

http://www.bioenergy-business.com/index.cfm?section=europe&action=view&id=10424

More depth here :

http://tinyurl.com/27cl3o

[warning : PDF!]

Your detailed article mentions ETBE and biobutanol, both of which have big advantages over bioethanol for aviation use. I understand several companies are looking at supplying forecourt fuel with these and one is considering marketing an Unleaded specifically suitable for light aviation use. I have no timeframe on when a decision will be announced, but the PFA are working on it.

Rod1

The petrol you buy in a forecourt can come from anywhere. Fuel companies regularly purchase fuel from rival companies when it's cheaper for them to supply a particular station. Some will indtroduce additives in to the tanker before delivery but things like ethanol are blended in at the refinery.
Therefore, it's not true to say 'all xyz company fuel has 5% in it'. The only way you can find out is to ask at the till. They are legally required to tell you what was in the latest delivery.

The petrol you buy in a forecourt can come from anywhere. Fuel companies regularly purchase fuel from rival companies when it's cheaper for them to supply a particular station.

I can confirm this is correct. My sister works for one of the large oil companies and I was taken for a guided tour around the plant. The first thing I noticed was all the tankers from different fuel companies and supermarkets lined up in a queue for refilling.

When I mentioned my surprise at this in the control office they all laughed!