What is the correct ventilation time for an engine before starting after fueling?

The correct ventilation time for an engine before starting after fueling is typically 4-5 minutes. This duration is important because it allows any potentially hazardous vapors from the fuel to dissipate. Fuels can emit gas that could pose a risk of explosion or fire if ignited, especially when the engine is cold and potentially has sources of ignition nearby.

Ventilating the area sufficiently ensures that any fumes are expelled and replaced with fresh air, reducing the likelihood of ignition. While less than 4 minutes might not provide adequate dispersion, extending the time beyond 5 minutes may be unnecessary and could delay operations. Thus, the 4-5 minute mark strikes a balance that ensures safety without prolonging the startup process unduly.