![](https://cdn.austrian-standards.at/thumbnail/shop/Product_Icons/118162/image-thumb__118162__as_book_product_detail_preview/Icon_ISO.png)
![](https://cdn.austrian-standards.at/thumbnail/shop/Product_Icons/118162/image-thumb__118162__as_organization_pdp_logo/Icon_ISO.png)
ISO 5164:2005
Issue date: 2005 06 10
Petroleum products — Determination of knock characteristics of motor fuels — Research method
ISO 5164:2005 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.
T ISO 5164:2005 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 5164:2005 can be used for oxygenate-containing fuels containing up to 4,0 % (m/m) oxygen.