93 AKI PUMP GAS FUEL RULE
1. Permitted Fuel
Only commercially available automotive pump gasoline rated 93 AKI [(R+M)/2] or lower is permitted.
Legal fuel must:
● Be sold to the general public for highway use.
● Be dispensed from a normal retail service-station fuel pump.
● Display a pump rating of 93 AKI or lower.
● Contain no more than 15% ethanol by volume.
● Be used in the same formulation in which it was dispensed from the retail pump.
The competitor is responsible for ensuring that all fuel in the vehicle complies with this rule.
2. Prohibited Fuel
The following are prohibited:
● Racing gasoline or race fuel.
● Aviation gasoline.
● Leaded racing fuel.
● E20, E30, E50, E85, or any fuel containing more than 15% ethanol.
● Methanol.
● Nitromethane.
● Propylene oxide.
● Specialty competition fuel.
● Any fuel marketed primarily for racing or motorsports use, even if its advertised octane rating is 93 AKI or lower.
● Any fuel not intended for normal highway passenger-vehicle use.
A race-fuel pump located at a racetrack, performance shop, or specialty fuel distributor does not qualify as a legal retail pump source under this rule.
3. Fuel Additives
No additive may be added to the fuel after it is dispensed from the retail pump.
This includes, but is not limited to:
● Octane booster.
● Ethanol.
● Methanol.
● Oxygenates.
● Fuel performance enhancers.
● Top-end lubricant.
● Injector cleaner.
● Fuel-system cleaner.
● Combustion enhancer.
● Any chemical intended to alter combustion, octane, oxygen content, charge cooling, or power output.
Fuel must be raced in the same formulation in which it was purchased.
4. Mixing Fuel
Mixing different grades or brands of otherwise legal pump gasoline is permitted only if every fuel used in the mixture independently complies with this rule.
Mixing legal pump gasoline with any prohibited fuel or additive is prohibited.
5. Proof of Purchase
Race officials may require a competitor to identify:
● Fuel brand.
● Advertised octane rating.
● Station where purchased.
● Approximate purchase date.
Officials may request reasonable proof including:
● Fuel receipt.
● Electronic receipt.
● Photograph of the fuel pump.
● Credit/debit transaction.
● Other reasonable proof of retail purchase.
Proof of purchase does not prevent the fuel from being tested.
A receipt alone does not establish that the fuel in the race vehicle is legal.
6. Inspection Authority
Race officials may inspect or sample fuel from any competing vehicle at any time during the event.
Testing may occur:
● Before competition.
● Between rounds.
● Immediately after a run.
● After elimination.
● After a protest.
● At random.
No advance notice is required.
Refusal to provide an official fuel sample constitutes an automatic fuel-rule violation.
7. Sample Collection
Fuel samples must be collected by a race official or under the direct supervision of a race official.
The official sample must be taken directly from the vehicle through one of the following:
● Fuel tank.
● Fuel line.
● Fuel rail.
● Fuel drain.
● Fuel-cell drain.
● Other location approved by the technical inspector.
A competitor may not provide a separate container of fuel in place of a sample taken from the race vehicle.
When a full inspection is performed, officials should collect approximately 16 ounces of fuel when practical.
The sample may be divided into:
Sample A — Trackside testing
Sample B — Official sealed retention sample
Sample C — Competitor/appeal sample
Retention samples shall be sealed and identified in the presence of the competitor or representative.
8. Sample Identification
Each retained sample should contain:
● Competitor name.
● Car or race number.
● Date.
● Time.
● Event.
● Sample identification number.
● Official’s initials.
● Competitor’s or representative’s initials.
Refusal to initial a sample does not invalidate the sample if the official documents the refusal.
9. Ethanol Test
Fuel may contain no more than 15% ethanol by volume.
The official ethanol tester shall be used according to the manufacturer’s procedure.
A field reading of:
● 15% or less: Pass.
● Greater than 15% but less than 17%: Retest required.
● 17% or greater: Fail.
When a retest is required, three tests should be performed from the official sample.
The average of the three readings will determine the result.
An average reading of 17% or greater constitutes a fuel-rule violation.
10. Specific Gravity Test
Specific gravity may be checked using the official hydrometer.
Fuel temperature shall be recorded with every specific-gravity measurement.
Specific gravity is a screening and comparison test only.
Officials may compare a competitor’s fuel with:
● Known legal pump-gas samples.
● Control fuel purchased by race officials.
● Previously documented legal pump fuels.
A difference of approximately 0.005 specific gravity or greater from a comparable control sample may be considered abnormal and may trigger additional inspection.
An abnormal specific-gravity reading by itself does not automatically disqualify a competitor.
Legitimate pump gasoline may vary because of:
● Brand.
● Refinery.
● Season.
● Geographic region.
● Ethanol content.
● Gasoline formulation.
Specific gravity shall therefore be used to identify suspicious fuel, not to directly determine octane.
11. Water-Separation Test
Officials may perform a water-separation test to identify unusual amounts of alcohol or other water-soluble material.
The competitor sample should be tested using the same quantities and procedure as a known legal pump-gas control sample.
An abnormal result may trigger additional testing.
A water-separation result alone does not constitute an automatic disqualification unless the test clearly demonstrates ethanol or another prohibited component above the permitted limit.
12. Control Fuel
Race officials may maintain samples of known legal pump gasoline for comparison.
Control fuel should be:
● Purchased directly by race officials.
● Purchased from a normal public retail service station.
● 93 AKI or lower.
● Stored in a clean sealed container.
● Clearly identified.
Records should include:
● Brand.
● Octane.
● Station.
● Date purchased.
● Ethanol content when known.
● Specific gravity.
● Fuel temperature when tested.
13. Abnormal Fuel
A fuel sample may be considered suspicious when one or more of the following occurs:
● Ethanol content is abnormal.
● Specific gravity is substantially different from normal pump gasoline.
● Water-separation behavior is abnormal.
● Fuel appearance is abnormal.
● Fuel source cannot reasonably be verified.
● Evidence indicates race fuel or another prohibited product was used.
● Evidence indicates an additive was introduced after purchase.
A suspicious screening result does not automatically establish a violation unless specifically stated elsewhere in this rule.
Officials may retain the sealed sample for additional analysis.
14. Confirmation Testing
When necessary, officials may submit the sealed official sample for independent analysis.
Confirmation testing may include:
● Ethanol concentration.
● Alcohol identification.
● Oxygenate analysis.
● Hydrocarbon analysis.
● Lead content.
● Prohibited additive analysis.
● Fuel density.
● RON.
● MON.
● AKI.
● Other appropriate chemical analysis.
A confirmed laboratory result may be used as the final determination of fuel compliance.
15. Octane Requirement
The maximum permitted retail pump rating is 93 AKI [(R+M)/2].
Because the standard trackside equipment used by the class does not directly measure AKI, competitors shall not be disqualified solely because a hydrometer or ethanol tester is alleged to indicate octane above 93.
Compliance with the 93-AKI requirement may be established through:
● Retail fuel-source verification.
● Official direct-octane testing equipment when available.
● Laboratory analysis.
● Other reliable evidence showing the fuel exceeds the permitted rating or is a prohibited product.
16. Automatic Fuel Violations
The following constitute an automatic fuel-rule violation:
1. Confirmed ethanol content of 17% or greater under the official testing procedure.
2. Race fuel found in the vehicle.
3. Aviation gasoline found in the vehicle.
4. E85 or another prohibited alcohol fuel found in the vehicle.
5. Methanol or nitromethane found in the vehicle.
6. Confirmed use of octane booster or another prohibited additive.
7. Confirmed fuel exceeding 93 AKI.
8. Sample substitution.
9. Sample tampering.
10. Refusal to provide a fuel sample.
11. Intentional interference with fuel inspection.
12. Knowingly providing false fuel-source information.
17. Competitor Appeal
A competitor wishing to challenge a fuel ruling must notify the race director or designated technical official before leaving the event grounds, unless otherwise authorized by the race director.
The appeal shall be based upon testing of the sealed official retention sample or other sealed sample approved by the race director.
All costs associated with an appeal, laboratory testing, shipping, handling, analysis, or independent verification shall be paid entirely by the competitor requesting the appeal.
The competitor may be required to pay the estimated testing and shipping cost in advance before the sample is released or submitted for testing.
The event promoter, race director, sanctioning organization, track, or technical staff shall not be responsible for the cost of appeal testing, regardless of whether the appeal confirms or overturns the original ruling.
The testing laboratory or testing facility shall be selected or approved by the race director or sanctioning organization.
The sample must remain sealed and maintain documented chain of custody until received by the approved testing facility.
If the approved independent test confirms that the fuel complies with these rules, the original fuel disqualification shall be reversed.
If the approved independent test confirms that the fuel does not comply with these rules, the original disqualification and any applicable penalties shall remain in effect.
Failure to pay the required appeal-testing costs or complete the appeal process within the time period established by the race director shall constitute withdrawal of the appeal.
18. Penalties
A confirmed fuel violation results in disqualification from the affected competition.
Additional penalties may be imposed for:
● Intentional use of prohibited fuel.
● Sample tampering.
● Repeated violations.
● Deliberate attempts to defeat testing.
Additional penalties shall be handled under the event’s general disciplinary rules.
19. Residual Fuel
Competitors are responsible for ensuring that prohibited fuel from previous operation has been removed from the fuel system.
Claims that illegal fuel was:
● Left over from a previous event.
● Accidentally present.
● Added by another person.
● Already in the fuel cell.
● Mixed unintentionally.
do not automatically excuse a failed fuel test.
Competitors changing from race fuel to pump gasoline should completely drain or flush the fuel system before competing.
20. Pre-Approval
A competitor uncertain whether a particular gasoline complies with this rule should present the fuel information to race officials before competition.
Pre-event approval of a fuel source does not permit the competitor to modify that fuel after purchase.