Description

This article is from the Gasoline FAQ, by Bruce Hamilton with numerous contributions by others.

6.6 What does the Research Octane rating measure?

The Research method settings represent typical mild driving, without
consistent heavy loads on the engine.

Test Engine conditions               Research Octane
Test Method                         ASTM D2699-92 [105]
Engine                       Cooperative Fuels Research ( CFR )       
Engine RPM                               600 RPM
Intake air temperature       Varies with barometric pressure 
                           ( eg 88kPa = 19.4C, 101.6kPa = 52.2C )
Intake air humidity           3.56 - 7.12 g H2O / kg dry air
Intake mixture temperature            Not specified 
Coolant temperature                      100 C
Oil Temperature                           57 C
Ignition Advance - fixed            13 degrees BTDC 
Carburettor Venturi           Set according to engine altitude          
                           ( eg 0-500m=14.3mm, 500-1000m=15.1mm ) 

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