Most, but not all, present petrol contains 5% ethanol but the intention is to increase this additive to 10% from some time in 2013.  This petrol will be labelled E10 on the pumps and elsewhere.  Any petrol pump not labelled E10 will have the E5 or even no ethanol content.  The adding of ethanol presents some problems for older vehicles.  Even the E5 has been known to attack some tank sealants, causing them to break away and clog filters.  Some motor cycles have fibreglass tanks and prolonged use of E5 can dissolve the binder.


Ethanol absorbs moisture from the air and holds it in solution.  A vehicle in daily use should have no problems with this, but older cars, likely to stand unused for long periods, may find the absorbed water attacks ferrous parts, like fuel tanks, and causes corrosion.  So far, no-one has produced a sealant resistant to E10, but various firms market an additive to go in the petrol to stop this corrosion.  The Federation of British Historic Vehicle Clubs has tested a number of these additives and the following five have been shown to work:

            Millers Oils                           VSPe Power Plus



            Frost ART Ltd                      Ethomix

            Flexolite Ltd                         Ethanolmate


The club has arranged to stock Millers VSPe through Robin Cooke’s good offices and this is now available to members at a substantial discount from the normal retail price.  Details are in the Spares News (attached) and in the Spares section of the club website.


It must be stressed that these additives only combat the corrosion problem and have no effect on the other problems associated with E10, such as vapour locking in hot weather, lean running and fungus forming in fuel pipes.  There is also a problem with some plastics and synthetic rubbers, although it is doubtful if many of these will be found in a Lagonda.  But fuel pump diaphragms could be at risk and possibly carburettor floats if the metal ones had been replaced with plastic ones.

Arnold Davey          December 2012