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Air-Fuel Ratio

The amount of air in proportion to the amount of fuel is known as the air-fuel ratio. The engine cannot perform efficiently if the fuel is too much or too little to the air volume. In most cases, the fuel-to-air ratio of a gasoline engine must be just correct to ensure good combustion in the cylinders. A suitable air-fuel ratio is crucial because the amount of air-fuel mixture drawn into the cylinders determines engine power performance.

  • Ideally, the most efficient air-fuel ratio mixture possible is 14:7:1 and best recommended for idling and light throttle conditions. If there are shift occurrences in this ratio, a harmful impact may cause on the engine and overall performance.
  • Some of the symptoms that indicate too rich or too lean air-fuel ratio are the occurrence of black smoke vibration, jerking, and poor acceleration. which is commonly brought by the following causes: faulty oxygen, camshaft position sensors, and fuel injectors, worn-out air filters.


  • The best way to check if your vehicle is in the proper ratio  is to check by a multi-use tester or scanning tool to run diagnostics to detect if there are existing trouble codes in relation to the unbalanced air-fuel mixture,