V8 SPEEDST 2 5/8IN AIR/FUEL RATIO F

A Holley Air/Fuel Ratio Gauge is an electronic instrument designed to monitor an internal combustion engine's air-to-fuel mixture in real-time. It typically displays data from a wideband oxygen sensor, enabling tuners and enthusiasts to optimize engine performance and efficiency. These gauges are essential for diagnosing rich or lean conditions, ensuring proper fuel delivery, and preventing potential engine damage. They are available in various sizes and display types, commonly featuring digital or analog readouts with sweep-style needles or segmented LED displays. Installation usually involves connecting to a 12V power source, ground, and a compatible wideband oxygen sensor (sold separately or as part of a kit).