RECIPROCATING ENGINE FUELS
a. Aviation gasoline (AVGAS) is obtained by adding high-octane components, ethyl liquids and antioxidants to
light fractions of petroleum or products of catalytic cracking.
b. The greatest difference among various grades of AVGAS is in anti-knock quality. However, properties in
addition to knock are closely controlled by speciications so that the gasolines will perform properly.
c. Grade 100/130 aviation gasoline is the only grade available in the Army supply system. The other grades,
if authorized for use, may be procured by local purchase.
d. When necessary, the different grades of aviation gasoline conforming to ASTM-D910 grades and also those
designated by NATO code numbers as listed in Table 2-5, may be used as speciied in Table 2-6 under alternate fuel.
a. Gasolines may be colored for purposes of identiication and gasolines containing TEL are required by law
to be colored.
b. Grade 80/87 aviation gasoline is red, 100/130 is green, 115/145 is purple and commercial 100LL (low lead)
AVGAS is blue.
(1) A change of color of an aviation gasoline usually indicates contamination with another product or a loss in
fuel quality. A color change can also be caused by a chemical reaction that has weakened the lighter dye component.
This color change in itself may not affect the quality of the fuel.
(2) A color change can also be caused by the preservative in a new hose. Grade 115/145 gasoline that has
been trapped for a short period of time in new hose may appear green. Flushing a small amount of gasoline through
the hose usually removes all traces of color change.
(3) During the period of transition from 115/145 to 100/130 grade as the Army Standard Fuel, there will
be a color change resulting from mixing 115/145 purple with 100/130 green, or 100 LL blue in drums, tanks and
a. Engine operating limits shall not exceed those prescribed for the fuel grade in use. When operating on
mixed grades of AVGAS the engine operating limits shall be those speciied for the lowest grade of fuel in the tank.
b. When using a fuel (or mixture) other than the standard Army fuel 100/130 (or NATO equivalent), the applica-
ble operator s and maintenance manuals should be referred to for special operational and maintenance procedures,
so that power settings may be revised, commensurate with the grade of fuel in use. When going to a higher grade
fuel, the published power settings or curves will be adhered to for all light conditions.
c. When changing from one grade of fuel to another, for example, for 100/130 to 115/145, it is not necessary
to drain the aircraft fuel system before adding the new fuel.
d. Motor gasoline should not be used in aircraft engines. Because of the special requirements of aircraft
and their engines, aviation gasolines differ from motor gasolines in distillation characteristics, vapor pressure, and
tetraethyl lead content. Furthermore, dissimilar lead compounds are used in the two types of fuels.
No emergency fuels are speciied for reciprocating aircraft engines.