Appendices - Hirohito's War
APPENDIX N: THE ROLE OF OIL IN THE PACIFIC WAR
Aviation Gasoline: In World War I aviation was still in its infancy and gasoline used for airplanes was essentially the same as that used for motor vehicles. Previously, dealing with the problems arising from the quality of fuel was not prioritized. If a car engine came to a halt nobody died; the same was not true in the air. During the war stricter rules were developed for the production of aviation gasoline; these included selection of suitable crude sources and the use of natural gasoline with kerosene distillate. Interest in aviation gasoline regressed after the war though in the mid 1920s oil companies did begin to ship their production with specification as to color, odor, un-saturation (the percentage soluble in sulphuric acid), Doctor Test gravity and distillation range. Only in 1927 did government first intervene to specify the qualities of aviation gasoline and indeed motor gasoline. Prior to that the seeming indifference to gasoline standards not only reflected the relatively novel technologies of the user industries but also the lack of methodology for testing petroleum quality.
As the 1930s progressed the oil companies produced higher and higher octanes of fuel, which allowed engines to burn fuel at higher temperature and higher power output – without the ‘knocking’ sound that characterized fuel with more impurities. Higher octanes allowed engines to operate at higher compression rates. By the later 1930s the US had developed aero engines that could use fuel refined at 100 octanes. By comparison Japanese pre-war engines were designed to operate at 87 octanes.
Perhaps most importantly the development of higher performing aero engines and fuel, combined with advances in airframe design, had by the early 1930s transformed the potency of aircraft; like the tank it was another weapon that massively increased the mobility of firepower.