Ethanol-blended Auto Fuel

  • Some fuel companies are about to launch 10% ethanol blended fuel in New Zealand.
  • Be aware that using such fuel is NOT recommended for aviation engines, including microlights.
  • Using such fuel increases the risk of reduced power, water absorption, carburettor icing, vapour lock and deterioration of rubber parts.
  • Pumps dispensing ethanol blended fuels are required to be clearly marked.
  • When buying fuel from a service station, be sure to positively identify the fuel is not ethanol blend.

CAA statement on ethanol blended fuels

The Civil Aviation Authority has been advised that the Environment Efficiency and Conservation Authority will very shortly announce the availability of ethanol-blended auto fuels in New Zealand. Auto fuels free of ethanol will still be available however, and AVGAS remains unchanged.

The blend will contain a maximum of 10% ethanol. All retail pumps selling ethanol-petrol blends must be labelled.

The FAA and Cessna have declared ethanol-blended fuels as inappropriate for aircraft use. The UK CAA do not permit the use of auto fuel containing alcohol.

The Experimental Aircraft Association (EAA) also consider the use of ethanol-blended fuels inappropriate due to:

  • Increased possibility of vapour lock at high temperatures
  • Slush formation at low temperatures due to the high attraction of water to ethanol
  • Material compatibility over a period of time.

The Civil Aviation Authority accepts the position taken by the EAA and the foreign authorities and will issue an Airworthiness Directive (AD) to ensure that aircraft operating on automotive fuels will not be fuelled with an ethanol-blended product.

The Airworthiness Directive will apply to a significant number of microlight and experimental category aircraft.

Further details will be posted here, and advice sent to the Aircraft Owners and Pilots Association, Sport Aircraft Association, Recreational Aircraft Association of New Zealand, and Sport Aviation Corporation.