52mm Racing Gauge AFR with Narrowband O2 Sensor and 12V Voltmeter

Key Features

• Dual Gauge Function — Combines an air-fuel ratio gauge and a voltmeter in one 52mm housing, so you read both on a single unit.
• Narrowband O2 Sensor — A narrowband O2 sensor is included to measure the air-fuel mixture in the exhaust.
• 12V DC Operation — Runs on DC 12V and works with most gasoline vehicle electrical systems to monitor battery voltage and charging output.
• Durable Plastic Shell — The plastic shell resists daily wear and keeps the gauge looking good on the dashboard.
• Black Racing-Style Housing — The black housing adds a sporty look to the interior without being flashy.

Product Specifications

• Color: Black
• Material: Plastic Shell
• Dimensions: 52mm (2.05 in)
• Weight: 350 g / 12.3 oz
• Power: DC 12V
• Placement on Vehicle: Front

What It Is / How It Works

This 2-in-1 digital gauge is an air-fuel ratio (AFR) monitor combined with a voltmeter. It uses a narrowband O2 sensor to measure the air-fuel mixture in the exhaust, and the digital display shows whether the engine is running lean or rich.

Who It's For / Use Cases

Gauges of this kind suit car enthusiasts who want to watch the air-fuel ratio while tuning or troubleshooting an engine. DIY mechanics fitting aftermarket gauges in project cars or trucks are another common group, as are motorcycle owners with 12V systems who want a compact, universal gauge.

How to Use / Care

1. Connect the narrowband O2 sensor to the exhaust to read the air-fuel mixture.
2. Mount the gauge in a dash or gauge pod using a 52mm / 2-inch hole or a standard 52mm pod holder.
3. Connect the gauge to the DC 12V electrical system to read the voltmeter display.
4. Read the digital display to see whether the engine is running lean or rich.

How to Choose

Start with mounting space. The 52mm diameter fits standard gauge pods and holders, so measure the opening before ordering.

Match the electrical system. This unit runs on 12V DC and is designed for gasoline engines, so it suits 12V gasoline vehicles rather than diesel engines.

Frequently Asked Questions

Does this gauge work with diesel engines?
No. It is designed for 12V gasoline engines only, and its narrowband O2 sensor measures exhaust from gasoline combustion.

What size hole does it need?
It needs a 52mm / 2-inch diameter hole or a standard 52mm gauge pod holder.

Is the sensor included?
Yes, one narrowband O2 sensor is included with the gauge.

Can I use it to tune my engine for racing?
Yes. The AFR reading helps you adjust the fuel mixture, and the gauge is a useful tool for tuning carburetors and fuel injection systems.

Does it come with installation instructions?
The gauge includes basic wiring guidelines. Some experience with automotive electrical systems helps with a proper installation.