Air fuel ratio gauge gives accurate readings on air and fuel available for combustion in turbocharged engines. It displays the richness or leanness of the exhaust mixture. Rich mixture has excess oxygen and lean mixture has less than enough oxygen. Ideal mixture is termed to as Stoichiometric or Stoich ratio, which is between the two extremes and usually spots as blinking of orange coloured LED.

Air fuel ratio has significant advantages as the driver gets accurate reading of oxygen levels; ensures optimum performance of catalytic converter, thereby reducing emissions; enhances fuel economy and prepares the engine for maximum performance.

The two types of air fuel ratio gauge are narrow band and wide band. The difference in oxygen sensors gives the gauges its name. Narrow band oxygen sensor is just enough for street vehicles. High performance vehicles require a wide band oxygen sensor for more accurate readings of oxygen levels and saturation levels of the air with fuel vapour. Wide band is also desirable for turbocharged, highly tuned vehicles.

The air fuel ratio gauge spots 10 LEDs, with colours green, yellow, orange and red. Taking a quick look on to the gauge, the driver can follow the exact conditions going on at the engine, on a real time basis. It takes a minute learn the factors for optimum performance, acceleration, fuel saving, etc.

If you have a turbocharged engine, air fuel ratio gauge is an essential addition. It doesn’t cost much and fits snugly on to the dashboard, giving you a convenient, reliable reading of the conditions at the engine.