How long before starting after refueling should you run ventilation?

• A. 1 minute.
• B. 4 minutes.
• C. 10 minutes.
• D. 30 seconds.

Answer: (B)

Ventilation after fueling is about removing gasoline vapors that can accumulate in the bilge or engine compartment. Gasoline vapors are flammable and heavier than air, so they can linger and ignite if an ignition source is present when you start the engine. Running the ventilation blower for about four minutes before starting the engine gives enough time for these vapors to dilute and vent away, reducing the fire risk. Shorter times, like one minute or 30 seconds, may not clear the vapors adequately, while much longer times (like ten minutes) aren’t typically necessary in this context. Four minutes strikes a safe, practical balance for clearing fumes.