This is not another dig at BP, I wouldn’t do that to you.
You may know this already. In the UK we now have 5% ethanol added to our petrol (when I did school chemistry it was known as Ethyl Alcohol). This percentage is soon to increase to 10%.
On the face of it this seems a good idea. Anything to wean the world off fossil fuels has to be taken seriously. What isn’t widely known is that ethanol is hygroscopic, it absorbs moisture from the atmosphere and as a result it corrodes steel containers. Ethanol also disolves fibreglass fuel tanks and there are many of these still around. The longer this petrol is stored in steel tanks, particularly if there is air space above the fuel, the more moisture it will absorb and the more corrosive it becomes. Older vehicles are already suffering from corrosion of the metals used in their carburettors and their fuel pumps. Many older fuel tanks (including a tank on one of my bikes) have been given an internal anti-corrosion coating. And guess what? This coating dissolves in ethanol to produce a foul glue that clogs up everything in sight (I should have said out of sight, because it’s all hidden away in the fuel system). Ethanol also rots rubber seals. Don’t think that it is only owners of classic cars and bikes who are affected by this. There are hundreds of thousands of older petrol engines out there, on generators, mowers, cultivators, boats, water pumps, and in farm and contractor’s machinery. All are in danger of damage by today’s petrol.
All of these problems seem trivial compared to the damage this obsession with ‘green’ fuels is doing elsewhere. Land previously used for food crops is now being used to produce biofuels (for diesel as well as petrol). We cannot afford to use our arable land to produce this stuff. The amount of grain required to produce enough ethanol to fill the fuel tank of a large car could feed one person for a year. Indonesia thinks it has the answer to this, and to get more land for biofuel crops it is felling an area of rainforest the size of 300 football pitches every HOUR. See here.
For an excellent and detailed information sheet on the problems (and some solutions) surrounding the use of biofuels in older engines see here. For more on the global problems we are making for ourselves by growing biofuel crops, simply google ‘deforestation diesel’.