Looking to give your 5.9L Cummins a cleaner, more consistent fuel supply while protecting the VP44 injection system? The AirDog II-5G combines a high-flow lift pump with water separation, fuel filtration, and air separation into a single system, addressing several of the factory fuel system's weak points at once. Available in 100, 165, and 220 GPH configurations, the AirDog II-5G can be matched to everything from stock and mildly modified trucks to high-demand performance builds. The system draws fuel through a large 1/2-inch suction line, removes water and particulates before the fuel reaches the injection pump, and separates entrained air before returning it to the tank for a more consistent fuel supply.
The AirDog II-5G uses a 4-bearing Gearotor pump with dual-feed operation to reduce cavitation, along with a built-in adjustable diaphragm regulator preset at approximately 17 PSI and adjustable up to 55 PSI. The integrated water separator removes 92% of water per SAE J1488, while the 2-micron fuel filter provides fine fuel filtration before the fuel reaches the injection system. The system also features demand-flow operation, returning only the air and excess fuel the engine doesn't require, and includes the vehicle-specific installation components needed for a clean installation. 100 GPH versions are available for trucks with the original block-mounted pump or an in-tank pump, the 165 GPH version is offered for trucks with an in-tank pump, and the 220 GPH system provides additional capacity for high-demand applications.
Which Flow Rate should you choose?
When it comes to upgrading your fuel system, choosing the right GPH (gallons per hour) rating isn’t about picking the biggest number; it’s about matching your pump to your truck’s real-world demands. An AirDog aftermarket fuel system doesn’t just supply fuel; it improves filtration, removes air/vapor, and ensures your injection system gets consistent, reliable pressure. But choosing between 100, 165, and 220 GPH? That’s where a lot of people get stuck.
100 GPH: Stock Reliability Upgrade (STOCK-500 HP)
- Perfect for stock trucks or very mild setups. If you want to eliminate factory fuel issues and improve reliability without overbuilding your system, this is the ideal choice.
165 GPH: Daily Driver + Towing Sweet Spot (500-800 HP)
- Best for trucks with mild tuning or regular towing. This is the most popular option for owners who want extra fuel capacity without going overkill.
220 GPH: Performance Builds (800-1100 HP)
- Designed for higher horsepower setups with increased fuel demand. Ideal for trucks running upgraded injectors or pushing harder under load.