A Pine Tree and Your Fuel

The Jeffrey pine is a big, reddish-barked California mountain pine tree that usually grows between 6,000 and 9,000 feet (1,800 and 2,700 m) above sea level. While it is an excellent lumber tree, it is also the source of an ingredient that is vital to the grading of fuel.

The book Discovering Sierra Trees explains: “The first intimation that Jeffrey pine contained a peculiar petroleum-based chemical came in 1867 when a turpentine distiller . . . unwittingly charged his still with pitch from Jeffrey pine rather than the usual ponderosa [pine] pitch. In the middle of the operation his still exploded. Later, a chemical called abietin was isolated in Jeffrey pine pitch. Abietin contains 96% normal heptane, a hydrocarbon also found in petroleum, and it was discovered that a purer and cheaper heptane could be produced from Jeffrey pine than by any other method. Heptane thus derived was used as a permanent and dependable ‘yardstick’ for grading fuels under a system called ‘octane rating.’”

So the next time you check the octane rating of your fuel, remember the role of the California Jeffrey pine.