ETHANOL

 

Most of us have used it and my preference is a 5% solution of ethanol in water flavoured with malt and hops whereas others prefer a 12% solution flavoured by grapes.  All of this ethanol is produced by the action of yeast on sugar.

However in future all of us will be using it as it will be added to petrol.  It has been legal to add up to 5% of ethanol to petrol in the UK since 2003 but there has been very little added until comparatively recently.

Ethanol is made from renewable resources and all governments in developed countries have been under pressure to increase its use in petrol.  It has been in widespread use in Brazil for many years and cars there are specifically designed to use 100% ethanol.

Ethanol has the potential to cause problems in older cars, and the older they are the more likely that problems will be encountered.  Pre-1930 cars will potentially have most problems but all classic cars may be affected.

Although it has been legal to add ethanol to petrol since 2003 its use in the UK has been limited and between 2003 and 2007 the average content was less than 1%.  The percentage has slowly been increased to the current average of 3.5% but some fuel companies are already adding 5% of ethanol to their Normal 95 RON unleaded fuel.  Most of the brands of Super Unleaded do not contain ethanol at the moment.

There is no requirement to display the ethanol content of any fuel that contains up to 5% but above that the pumps will have to be labeled and E10 is already the standard fuel across many countries in Europe.  Beware in France of the pumps marked E85 which will dispense fuel containing 85% ethanol which is guaranteed to cause problems in cars not specifically designed for that fuel.

So what are the problems that may be experienced?

The volatility of modern fuels is such that problems of poor slow running, poor hot starting and running on are more likely.  One of the problems with ethanol is that it is a powerful solvent.  Rubber and gasket seals that were originally designed to seal mineral oils and oil based fuels can be attacked by organic solvents, of which ethanol is one, and leaks will occur.  It is quite likely that 5% ethanol will not cause significant problems but when the content is increased to 10% failure of rubber seals will become much more likely.

Another problem with ethanol is that it is hygroscopic, meaning that it absorbs water from the atmosphere and in cars that have long storage periods, for example over the winter, there will be a significant chance of  rust occurring in fuel tanks and lines.  If you have a transparent fuel filter bowl keep an eye open for brown staining.  Ethanol is also likely to dislodge debris that has built up over many years and had been stable with older fuels.  This will cause filter blocking.

Finally another feature to be aware of is the chemical make-up of ethanol which is a mix of carbon, hydrogen and oxygen.  It contains quite a lot of oxygen and when a fuel containing ethanol is burnt this oxygen is available for combustion and will have the effect of weakening the mixture which may show up as hotter running.

So be aware and avoid pumps marked E10 for as long as you can.  Or you could always have a diesel engine in your classic car as biodiesel does not have the same problems – merely other ones!

 

JD