Ethanol Blend Specifications

Ethanol-blended gasoline sold in the state must meet ASTM specification D4814, with the following exceptions:

  • The maximum vapor pressure of ethanol blends containing 1% or more ethanol for volatility Classes A, B, C, and D may not exceed the ASTM D4814 limit by more than 1.0 pound per square inch (psi); and
  • The maximum vapor pressure of ethanol blends containing 1% or more ethanol for volatility Class E may not exceed the ASTM D4814 limit by more than 0.5 psi
These exceptions remain in effect until ASTM develops final vapor pressure maximums for ethanol blends. (Reference Tennessee Code 47-18-1304)