Fuelab 54501-4 545 Series Mini EFI Inline Fuel Pressure Regulator 25-90 PSI Purple

The Fuelab 545 Series Mini Inline Fuel Pressure Regulator delivers all the performance of the full-size 525 Series in a compact, lightweight package — weighing 50% less without sacrificing capability. Designed for EFI applications, this adjustable regulator supports a pressure range of 25–90 PSID, making it well-suited for a wide range of fuel-injected builds. The purple anodized billet aluminum body provides a durable, corrosion-resistant finish that meets military specification MIL-A-8625, Type II.

The defining feature of the 545 Series is its in-line return port — positioned in-line with the inlet port rather than on the bottom of the unit. This design allows for hassle-free installation in tight engine bays where clearance is limited. Both port and non-port style union fittings are accepted without interference, offering maximum plumbing flexibility.

Key Features:

• Pressure Range: EFI 25–90 PSID
• Inlet Port: -6AN (1)
• Return Port: -6AN (1), in-line with inlet
• Seat Size: Standard
• Construction: Billet aluminum with Type II military-spec anodize (MIL-A-8625)
• Finish: Purple anodized
• Compatible with gasoline, diesel, methanol, and ethanol fuels
• Fine thread pitch for precise, repeatable pressure adjustment
• 1/8" NPT gauge port with plug for external fuel pressure gauge
• 1/8" NPT pressure reference port with barbed fitting
• Includes versatile mounting bracket with stainless steel hardware
• Compact dimensions: 1.50" D x 2.00" W x 2.25" H
• Weighs only 5.25 oz.
• Backed by a limited lifetime warranty

The Fuelab 54501-4 is sold individually and is a direct fit for performance EFI fuel systems requiring a compact, high-quality inline regulator. A 60-micron or finer fuel filter is recommended upstream of the regulator to protect injectors and internal components.