fueltoair

The term fuel-to-air ratio, often abbreviated as FAR, refers to the relative amount of fuel compared to the amount of air present in a combustion process. This ratio is a critical parameter in internal combustion engines and other combustion systems. It is typically expressed as a mass ratio, meaning the mass of fuel divided by the mass of air. The ideal fuel-to-air ratio for complete combustion, where all fuel and oxygen are consumed, is known as the stoichiometric ratio. Deviations from this ideal ratio can significantly impact engine performance, efficiency, and emissions.

A fuel-to-air ratio that is too low, meaning there is more air than needed for complete combustion, is called a lean mixture. Lean mixtures tend to burn cooler and can improve fuel economy but may lead to incomplete combustion of the fuel and increased nitrogen oxide (NOx) emissions. Conversely, a fuel-to-air ratio that is too high, with more fuel than can be completely burned by the available air, is called a rich mixture. Rich mixtures burn hotter, can produce more power, but result in incomplete combustion of the fuel, leading to increased carbon monoxide (CO) and unburned hydrocarbon (HC) emissions. Engine control systems precisely manage the fuel-to-air ratio to optimize performance and meet emission standards under various operating conditions.