Auto Meter 4328 Ultra-Lite Mechanical Nitrous Pressure Gauge

OVERVIEW

When you are pushing the limits of your air-cooled power plant with a nitrous oxide system, precision is not just a luxuryit is a requirement for survival. The Auto Meter 4328 Ultra-Lite Mechanical Nitrous Pressure Gauge is the industry gold standard for enthusiasts who demand high-stakes accuracy and a lightweight footprint. Whether you are staging a Pro-Street Beetle at the drag strip or dialling in a high-performance sand rail, monitoring your nitrous bottle pressure is critical to ensuring consistent solenoid operation and preventing lean conditions that can melt a set of forged pistons in seconds. The Ultra-Lite series has become a staple in the Volkswagen performance world because of its iconic satin anodized aluminum face and high-contrast red pointer, providing a professional racing aesthetic that complements any custom VDO or standard dash layout.

The mechanical movement of the ATM4328 offers a direct, real-time link to your nitrous supply, providing a 0 to 1500 PSI sweep that allows for instantaneous troubleshooting of your system. Unlike electronic gauges that may suffer from signal lag or electrical interference, this mechanical unit delivers the raw data you need to manage bottle heaters or determine if your bottle is running low. Constructed from premium aluminum to keep weight to an absolute minimum, this gauge is designed to withstand the vibrations and harsh environments common in off-road dune buggies and high-revving street cars. At Appletree Automotive, we know that performance is nothing without reliability, and the Auto Meter Ultra-Lite series delivers the rugged durability required to keep your VW running at the front of the pack.

FITMENT

This 2-1/16 inch (52.4mm) gauge is designed for universal mounting in any standard gauge pod or dashboard cutout. It is particularly popular for the following air-cooled applications:

• Volkswagen Beetle: All years and models (1946-1979)
• Volkswagen Karmann Ghia: All years (1955-1974)
• Volkswagen Type 2 Bus: Transporter, Kombi, and Microbus (1950-1979)
• Volkswagen Type 3: Squareback, Fastback, and Notchback (1961-1973)
• Volkswagen Thing: (1973-1974)
• Custom Sand Rails and Dune Buggies: Meyer''s Manx, Berrien, and tube chassis rails.
• Baja Bugs: Custom dash configurations and overhead consoles.

SPECS

• Product Series: Ultra-Lite Mechanical
• Gauge Type: Nitrous Pressure
• Pressure Range: 0-1500 PSI
• Gauge Size: 2-1/16 inch (52.4mm)
• Face Color: Satin Anodized Aluminum
• Bezel Color: Silver / Brushed Aluminum
• Pointer Color: Fluorescent Red
• Lighting: Incandescent (Includes red and green bulb covers)
• Connection: 4AN male fitting on the back of the gauge
• Movement: High-precision mechanical bourdon tube
• Mounting Hardware: Included (U-bracket and nuts)

PRO TIPS

1. Proper Line Routing is Key for Safety

Because this is a mechanical nitrous gauge, it requires a high-pressure line to run directly from your nitrous source to the back of the gauge. We strongly recommend using a high-quality stainless steel braided 4AN line. Ensure that the line is routed away from moving parts like your shift linkage or steering column, and use a firewall grommet to prevent the line from chafing. If you are mounting this inside the cabin of a street-legal Beetle, it is often a professional racing standard to use a nitrous pressure isolator. This keeps the actual nitrous gas outside the passenger compartment while still providing an accurate pressure reading to the gauge face.

2. Optimize for the 900-1000 PSI Sweet Spot

Most nitrous systems are engineered to flow the correct amount of fuel-to-nitrous ratio when the bottle pressure is between 900 and 1000 PSI. If your pressure is too low, the engine will run rich and lose power; if it is too high, the system will run lean, which can lead to catastrophic engine failure in an air-cooled flat-four. Use the Auto Meter 4328 to monitor your bottle heater''s effectiveness. If you see the needle climbing toward the 1100+ PSI range on a hot day, it is time to cool the bottle down or adjust your heater settings before making your next pass.

3. Visibility and Night Driving Adjustments

The Ultra-Lite series comes with red and green bulb covers to help you match your existing dashboard lighting. For air-cooled VWs with classic green dash lights, using the green cover provides a seamless OEM-plus look. Additionally, when mounting the gauge, try to angle it slightly toward the driver''s seat. In a high-vibration environment like a sand rail or a stiffly-sprung drag Bug, having the gauge oriented so you can see the 900 PSI mark at a "12 o''clock" position can make it much easier to verify your system status with just a split-second glance while you are shifting through the gears.