52 mm Air-Fuel Gauge with Wideband Lambda Sensor

52 mm air-fuel gauge — monitor your mixture in real time

This 52 mm air-fuel gauge displays your engine's air-fuel ratio in real time using the wideband lambda sensor included in the kit. A blue LED digital display shows the numerical value while a 20-segment bar graph changes from red to green, allowing you to instantly spot a mixture that is too rich or too lean. It is the essential tool for any serious engine tuning.

Why install an AFR gauge on your car

• Complete ready-to-install kit: 52 mm gauge, wideband lambda sensor, wiring harness and bracket included—nothing else to buy.
• Instant mixture reading: the AFR value updates several times a second, much faster than a stock narrow-band sensor.
• Engine protection: a mixture that is too lean under full load is the leading cause of failure in tuned or turbocharged engines.
• Dual display: the digital value for precision and the colored bar graph for reading while driving without taking your eyes off the road.
• Black smoked dial: invisible when the engine is off and highly readable both at night and in bright sunlight.
• Standard 52 mm diameter: fits all gauge brackets on the market, whether on an A-pillar, air vent or center console.

Who is this air-fuel ratio gauge for

The air-fuel ratio, or AFR, measures how many grams of air the engine burns for every gram of fuel. At around 14.7:1, the mixture is considered stoichiometric; under full load, a turbocharged engine usually requires 11.5 to 12.5:1. This gauge is therefore primarily intended for those who perform engine remapping, install an intake kit or free-flow exhaust, run on E85 ethanol, or prepare a track car. Unlike a stock narrow-band lambda sensor, the wideband sensor remains accurate far from the stoichiometric point, where it matters most.

Technical specifications

Diameter: 52 mm (2 inches). Voltage: 12 V. Display: blue digital LED and 20-segment bar graph. Measuring range: 10:1 to 20:1. Sensor included: 4-wire wideband lambda sensor. Secondary function: in-car voltmeter. Dial: black smoked. Installation: universal 12 V, gasoline. Included: gauge, sensor, wiring harness, bracket and hardware. Condition: 100% new.

Installation and maintenance

Allow 1 to 2 hours. The lambda sensor screws into an M18x1.5 bung on the exhaust system, ideally 30 to 60 cm after the manifold or turbocharger; if your system does not have one, a bung can be welded in or fitted with a clamp. Inside the cabin, three wires are sufficient: +12 V switched ignition, ground and lighting. Allow the sensor to heat up for about 30 seconds before the reading stabilizes. Maintenance: none, except wiping the glass with a microfiber cloth. Compatibility should be checked before installation depending on your exhaust system.

Frequently asked questions

What is the ideal AFR value to aim for?
Around 14.7:1 under partial load and 11.5 to 12.5:1 under full load on a turbocharged engine. Below 11, the engine will run rich; above 13 under load, it will overheat.

Can it be installed on a diesel engine?
No. This air-fuel ratio gauge and its sensor are designed for gasoline engines.

Do I need to drill into the exhaust system?
Yes, if there is no available bung: an M18x1.5 bung must be welded in. Many sport systems already have one, sealed with a plug.

Can the stock sensor be reused?
No, a narrow-band sensor does not provide a usable value under full load. This is why the wideband sensor is included.

Does the gauge turn off with the ignition?
Yes, if it is wired to a switched +12 V supply. It does not draw battery power when the engine is off.

Take control of your engine tuning: complete gauge and wideband sensor kit, instant reading, universal 12 V installation.

Type: Air-fuel ratio gauge
Diameter: 52 mm
Voltage: 12 V
Display: Digital LED and 20-segment bar graph
Sensor: Wideband lambda sensor included
Engine type: Gasoline
Installation: Universal, M18x1.5 bung
Condition: 100% New