Our air/fuel ratio meter has nineteen LEDS, seven red lights for lean mixture, five orange lights for mid range mixtures around the chemically correct air/fuel ratio of 14.7:1 (lambda=1) and seven green lights for rich mixtures. Race engines generally give most power with a lambda reading of 0.8 - 0.9, the meter will allow the tuner to correctly set the mixture to this level and allow the driver to ensure that the engine is never running dangerously lean. The meter is suitable for use on all petrol types and any 0-1V lambda sensors