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Fuel

Port Injection

Fuel sprayed into the intake port before the valve, mixing with incoming air.

Definition

Port injection keeps intake valves cleaner than direct injection alone.

Dual-injection systems combine port and direct injection for flexibility.

Related terms

  • Fuel InjectorAn electronically controlled valve spraying atomized fuel into the intake port o
  • CarburetorA mechanical device mixing fuel and air using jets, venturis, and throttle plate
  • Direct InjectionFuel injection directly into the combustion chamber at high pressure.
  • Octane RatingA measure of fuel resistance to knock under compression and heat.
  • E85A blend of roughly 85% ethanol and 15% gasoline offering high knock resistance.
  • Air-Fuel RatioThe mass ratio of air to fuel in the intake charge, critical for power and engin

Category: Fuel · Updated August 31, 2026