Misfuel Prevention Guide

Preventing misfueling is the best way to avoid costly damage and inconvenience. Follow these guidelines to protect your vehicle.

Understanding the Risk

Misfueling occurs when the wrong fuel type is put into a vehicle. The most common incidents are:

Gasoline in Diesel Vehicles: Most common—especially diesel pickups (Ford Power Stroke, Ram Cummins, GM Duramax), fleet vans, and passenger diesels—causing severe damage to high-pressure injection systems and DEF (Diesel Exhaust Fluid) components
Diesel in Gasoline Vehicles: Less common but equally damaging to spark-ignition engines and emissions equipment
Contaminated Fuel: Water or debris entering the fuel system through improper handling or storage

Prevention Tips

1. Always Check the Fuel Type

Before inserting the fuel nozzle, always verify:

Check your vehicle's fuel cap label and owner's manual
Confirm the pump dispenser label matches your vehicle (gasoline, diesel, E85, etc.)
At U.S. stations, diesel pump handles are often green or yellow (varies by brand); gasoline handles are typically black. Colors are not standardized—always read the pump label
Read the fuel grade on the pump display (Regular 87, Mid-grade 89, Premium 91–93 AKI; E10 is standard in most areas; E15 and E85 where labeled)

2. Use Visual Reminders

Create visual reminders to prevent mistakes:

Place a sticker on your fuel cap indicating fuel type
Use a fuel cap lock with a reminder tag
Keep a note in your vehicle's glove box
Set a reminder on your phone if you drive multiple vehicles

3. Be Extra Careful When Tired or Distracted

Most misfueling incidents occur when drivers are:

Tired or fatigued
Rushed or in a hurry
Distracted by phone calls or conversations
Driving a rental or unfamiliar vehicle

Take a moment to double-check before fueling.

4. Know Your Vehicle

Familiarize yourself with your vehicle's fuel requirements:

Check your owner's manual
Know the fuel type required (gasoline, diesel, E85, or other)
Understand octane and ethanol limits (e.g., many vehicles require 87 AKI minimum; some flex-fuel vehicles can use E85)
Diesel vehicles require ULSD and may use DEF—do not confuse DEF with fuel additives
Be aware of fuel cap location and design

5. Use Fuel Nozzle Size Differences

Many U.S. gas stations use different nozzle sizes:

High-flow diesel nozzles at truck lanes are larger (about 1 in. / 24 mm) and often will not fit passenger-car gasoline filler necks
Passenger diesel fillers may still accept a gasoline nozzle—so nozzle fit alone does not prevent gasoline-in-diesel mistakes
If a nozzle does not fit easily, STOP—you may have the wrong fuel type or wrong pump lane

6. For Fleet Operators

If you manage a fleet, implement these practices:

Color-code vehicles by fuel type
Provide clear training to drivers
Use fuel cards that restrict fuel type
Maintain clear documentation of each vehicle's fuel type
Have an emergency response plan

What to Do If You Misfuel

CRITICAL: DO NOT START THE ENGINE

If you realize you've misfueled before starting the engine:

DO NOT start the engine - This is critical
Do not turn the ignition key
Contact ONLY operators displaying the USIFDA Mark immediately
Have the vehicle towed to the operator's certified fixed facility if necessary
Do not attempt to drain the fuel yourself
Verify the operator displays the USIFDA Mark before engaging services

Starting the engine will circulate contaminated fuel throughout the system, causing extensive damage and significantly higher repair costs.

⚠️ Legal Warning: Customer Liability

Under U.S. law, you are responsible for ensuring contaminated fuel is handled by properly licensed operators.

Using illegal or unlicensed operators can result in:

Fines and penalties for using unlicensed waste disposal services
Liability for environmental violations if waste is improperly disposed
Responsibility for cleanup costs if environmental damage occurs
Voided insurance coverage

✅ Protect yourself: Only use operators displaying the USIFDA Mark. Illegal operators face federal and state enforcement; USIFDA reports them to authorities.