What Is Fuel Resistance?
Fuel resistance test is a test in which the sample is immersed in the reference fuel or liquid defined in the standard at a defined temperature and time; It is an experiment in which volume swelling, mass change, hardness and loss of mechanical properties are measured.
Purpose of Fuel Resistance
The aim is to verify that swelling and loss of properties of the elastomer in contact with the fuel system remain within acceptable limits.
Which Products Is Fuel Resistance Applied To?
- Fuel hoses and gaskets
- Fuel pump and injector elastomers
- Tank and cover gaskets
- Fuel system O-rings
In Which Sectors Is Fuel Resistance Used?
Standards Related to Fuel Resistance
- ISO 1817
- ASTM D471
- SAE J1681 (reference fuels)
- ISO 23529
Fuel Resistance Conditions
- Reference liquid
- Reference fuels defined in the standard (e.g. ISO 1817 liquids or SAE J1681 fuel mixtures)
- Temperature
- Defined in the specification; represents the service temperature
- Time
- Defined in the standard; typically 22, 70 or 168 hours
- measured change
- Volume change, mass change, hardness and tensile properties
Equipment for Fuel Resistance
- Closed dipping vessels and temperature-controlled bath
- Analytical balance and volume measurement setup
- Tensile tester and durometer
- Fume hood and flammable liquid storage
Sample Requirements for Fuel Resistance
- Initial measurements should be recorded
- Containers must be leak-proof; Loss of volatile component spoils the result
- Reference fluid freshness and composition must be documented
- The number of specimens is defined in the standard
Duration of Fuel Resistance
1–2 weeks depending on duration.
Fuel Resistance Procedure
- 1Samples are measured and weighed.
- 2The reference liquid is prepared and brought to temperature.
- 3Samples are immersed in a closed container for a defined period of time.
- 4Samples are removed and the surface is wiped according to the standard.
- 5Volume, mass and hardness are measured.
- 6Mechanical properties are measured and the change is calculated.
Fuel Resistance Acceptance Criteria
The acceptance criteria are the maximum volume swelling and property change limits given in the specification.
Evaluation of Results
The composition of the reference fuel (especially the aromatic and alcohol content) determines the swelling; Results obtained with different reference liquids cannot be compared. Biofuel and alcohol-containing fuels behave differently than traditional reference fuels and should be evaluated separately.
Fuel Resistance Report
- Applied standard and reference fluid
- Temperature and duration
- Before/after measurements
- Volume and mass change
- Mechanical property change
Accreditation
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.
Scope and authorisationsRelated Regulations
- Automotive fuel system specifications
Otomotiv Testleri — What Does This Testing Field Cover?
The section below describes the field that the Fuel Resistance 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.
Automotive testing shows that a component keeps working under conditions representing the loads it will meet over the life of the vehicle. A vehicle is not a single product but an ENVIRONMENT: vibration, temperature cycling, salt water, stone impact, electrical transients and electromagnetic noise are all present at the same time and for years.
What distinguishes this family is that VEHICLE MANUFACTURER SPECIFICATIONS sit on top of the standards. ISO and SAE publications establish the common ground; but Volkswagen, BMW, Ford, Stellantis, Toyota and Renault define different severity levels, additional tests and different acceptance criteria in their own specifications. For a component, the phrase "complies with automotive standards" is not sufficient on its own; which manufacturer's specification, and which revision of it, must be answered.
The family carries three separate processes together and they are often confused. Homologation covers the type approvals a vehicle needs to enter traffic and runs under state authority. Supplier approval means passing the vehicle manufacturer's own quality and testing requirements and is a commercial relationship. The third is design verification: the engineering team demonstrating that its own design meets its targets.
At component level the test plan is built around the LOCATION OF USE. A module in the engine bay and a module in the boot do not go through the same temperature and vibration profile; a component inside a door and one in the roof console do not see the same water and dust exposure. The ISO 16750 series is the common framework for this location-based approach.
The shift to electric vehicles has reshaped the field. High-voltage safety, insulation coordination, battery safety, charging interface conformity and the electromagnetic behaviour of high-voltage components have been added to the classical automotive test set. In a quiet vehicle, acoustic and vibration expectations have changed too; sounds once masked by the combustion engine are now audible.
The quality system side cannot be separated from testing in this field. A manufacturer under IATF 16949 presents test results in the PPAP file; measurement system analysis, process capability study and the control plan stand around the test report. A single good result is not enough — the process must be shown to be able to repeat it.
Method groups in this field
Environmental and climatic
Temperature cycling, thermal shock, damp heat, salt spray, dust and water ingress (IP), solar radiation. Severity levels vary with the mounting location.
Mechanical
Sine and random vibration, shock, mechanical loads, fastener torque and durability cycles.
Electrical
Supply voltage variations, transients (ISO 7637), reverse polarity, overvoltage, short circuit and sleep current measurements.
EMC
Component emissions (CISPR 25), radiated and conducted immunity (ISO 11452 series), electrostatic discharge (ISO 10605).
Materials and emissions
Odour, fogging and VOC emissions from interior materials; flammability; UV ageing; coating durability and stone impact.
Functional safety and cyber security
Functional safety evidence under ISO 26262 and cyber security engineering under ISO/SAE 21434; these are tied to regulation through UNECE R155 and R156.
Commonly confused in this field
- An automotive report without a specification reference is not accepted in the supply chain; which OEM specification and revision was applied must be stated.
- Type approval and supplier approval are different processes. A component with E-Mark approval is not thereby considered to have passed the OEM's own acceptance tests.
- A result obtained on a prototype does not carry over to series production; PPAP is done with series production parts.
- On the EMC side, measuring emissions alone is incomplete; immunity is a separate body of work and is more critical in a vehicle.
- On electric vehicle components, high-voltage safety is a distinct competence; classical 12 V test infrastructure is not sufficient.
Which decisions these results support
- Supplier component approval and the PPAP file
- UNECE type approval and E-Mark marking
- Design verification and durability evidence
- Root cause analysis of field complaints and warranty returns
- Assessing the impact of a design or supplier change
Related Tests
Frequently Asked Questions About Fuel Resistance
Is the gasoline resistance report valid for fuel with ethanol additives?
No. Alcohol addition significantly changes the swelling behavior of the elastomer. Separate testing with a reference fluid representative of the target fuel is required.