Octane

Octane number is a measure of the resistance of gasoline to engine knocking (premature ignition). In the CFR octane engine, the sample is compared to reference fuels of known octane number. Two values ​​are measured: RON represents the behavior at lower load and speed, MON represents the behavior at higher load and temperature.

The purpose is to verify that gasoline can run in the engine without knocking and to demonstrate its compliance with the specification class. Knocking can cause permanent damage to the engine.

• Unleaded gasoline (95, 98 octane)
• Ethanol blended gasolines
• Racing and special purpose fuels
• Refinery blending streams
• Oxygenate mixtures

• TS EN ISO 5164 (research octane number — RON)
• TS EN ISO 5163 (engine octane number — MON)
• ASTM D2699 / D2700
• TS EN 228 (gasoline specification)

Engine conditions

RON and MON are measured at different speed, mixture temperature and advance conditions

Reference fuels

Mixtures of isooctane and n-heptane

Specimen

Must be kept cold to prevent loss of volatile components

• CFR octane engine (RON and MON configurations)
• Reference fuel sets
• Knock measurement system
• Refrigerated sample storage

• Sampling determines the validity of the result in fuel analysis: ISO 3170 (manual) and ISO 3171 (automatic in-line) define the sampling rules. The sample must be taken into a clean container of a suitable material, filled with no air gap, and kept cold for volatile products.
• The sample should be filled without leaving any air space and kept cold.
• Sufficient volume is required for the motor method
• Should be reported if oxygenate content is known

Engine measurement takes time due to engine calibration and reference comparisons; RON and MON are separate measurements and the total time reflects this.

1. 1The CFR engine is configured and calibrated according to the relevant method.
2. 2Reference fuel mixtures are prepared.
3. 3The sample is fed to the engine and the knock intensity is measured.
4. 4Matching is done with reference fuels.
5. 5RON and MON are determined separately.
6. 6The results are compared to the specification limit.

The acceptance criterion comes from the relevant product specification and varies by season, market and class. Specification versions are updated; the limit values in force for your product are confirmed from the specification text at the quotation stage.

RON and MON are evaluated together; The difference (sensitivity) shows the behavior of the fuel under different operating conditions. Ethanol significantly increases RON, but its effect on MON is more limited; Therefore, in blended fuels, the two values ​​should be monitored together.

• Sample description and oxygenate content
• Applied standards
• RON and MON results
• Hassasiyet (RON−MON)
• Comparison against specification limits

EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.

Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.

• 98/70/EC Fuel Quality Directive

The section below describes the field that the Octane test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.

• Density
• Viscosity
• Flash Point
• Pour Point
• Cloud Point
• Cetane
• Sulfur
• Water
• TAN
• TBN
• Distillation
• Oxidation Stability