Supercharge method ratings can provide an indication of the rich-mixture antiknock performance of aviation gasoline in aviation piston engines.

Supercharge method ratings are used by petroleum refiners and marketers and in commerce as a primary specification measurement to insure proper matching of fuel antiknock quality and engine requirement.

Supercharge method ratings may be used by aviation engine and aircraft manufacturers as a specification measurement related to matching of fuels and engines.

1.1 This test method covers the determination of the knock-limited power, under supercharge rich-mixture conditions, of fuels for use in spark-ignition reciprocating aircraft engines, in terms of ASTM supercharge octane or performance number. By operational considerations, this test method is restricted to testing fuels of 85 ASTM supercharge octane number and over.

1.2 The values stated in inch-pound units are to be regarded as the standard. The values in parentheses are for information only.

This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in .