P-Series fuels are blends of natural gas liquids (pentanes plus), ethanol, and methyltetrahydrofuran (MeTHF), a biomass co-solvent. P-Series fuels are clear, colorless, 89-93 octane, liquid blends used either alone or mixed with gasoline in any proportion in flexible fuel vehicles. These fuels are not produced in large quantities and not used widely.

P-Series is the only fuel to be added to the Energy Policy Act of 1992 as an alternative fuel. It was added in 1999.


P-Series fuels can be an alternative to conventional transportation fuels. The benefits of P-Series fuels include:

  • More Flexibility—P-Series fuels can fuel modern FFVs.
  • Fewer Emissions—Vehicles fueled by P-Series fuels generally have fewer emissions than conventional vehicles fueled by gasoline.
  • Increased Energy Security—P-Series fuels can be manufactured from domestic natural gas and biomass feedstocks, reducing U.S. reliance on imported petroleum.

More Information

Learn more about P-Series fuels from the links below.

The AFDC also provides a publications search and a database of related links.