prEN ISO 5164 rev

Petroleum products — Determination of knock characteristics of motor fuels — Research method

General information

10.99   New project approved   Mar 21, 2026

CEN

CEN/TC 19 Gaseous and liquid fuels, lubricants and related products of petroleum, synthetic and biological origin.

European Norm

Scope

ISO 5164:2014 establishes the rating of liquid spark-ignition engine fuel in terms of an arbitrary scale of octane numbers using a standard single-cylinder, four-stroke cycle, variable compression ratio, carburetted, CFR engine operated at constant speed. Research octane number (RON) provides a measure of the knock characteristics of motor fuels in automotive engines under mild conditions of operation.
ISO 5164:2014 is applicable for the entire scale range from 0 RON to 120 RON, but the working range is 40 RON to 120 RON. Typical motor fuel testing is in the range of 88 RON to 101 RON.
ISO 5164:2014 is applicable for oxygenate-containing fuels containing up to 4,0 % (m/m) oxygen and for gasoline containing up to 25 % (V/V) ethanol.

Life cycle

PREVIOUSLY

PUBLISHED
EN ISO 5164:2014

NOW

IN_DEVELOPMENT
prEN ISO 5164 rev
10.99 New project approved
Mar 21, 2026