Fuelab 52501-5 525 Series In-Line EFI Adjustable Fuel Pressure Regulator 25-90 PSI Gold

The Fuelab 52501-5 is a precision-engineered, adjustable in-line fuel pressure regulator from the 525 Series, finished in a distinctive gold anodized coating. Machined from 6061-T6 billet aluminum and hand assembled, this EFI regulator is built for performance applications demanding stable, accurate fuel pressure control across a 25–90 PSI range.

The 525 Series sets itself apart with its in-line return port design — the return port runs inline with the inlet port rather than on the bottom, making installation far easier in tight engine bays and confined fuel system layouts. The regulator accepts both port-style and non-port-style union fittings without interference, adding versatility for a wide range of fuel system configurations.

Key Features:

• EFI adjustable pressure range: 25–90 PSID
• Single -6AN inlet and single -6AN return port, in-line configuration
• Return port in-line with inlet — not on the bottom — for easy installation in tight spaces
• Compatible with gasoline, diesel, methanol, and ethanol
• Machined from 6061-T6 billet aluminum, hand assembled, and serialized
• Anodized finish per military spec MIL-A-8625, Type II — Gold
• Fine thread pitch adjustment for precise pressure tuning
• Includes versatile mounting bracket and stainless steel hardware
• 1/8" NPT gauge port with plug for optional external pressure gauge
• 1/8" NPT pressure reference port with barbed fitting for MAP sensor referencing
• Backed by a limited lifetime warranty

The Fuelab 525 Series regulator is a top choice for EFI builds requiring a compact, reliable, and tunable fuel pressure solution. The gold anodized finish (MPN suffix -5) adds a premium appearance while the military-grade anodizing ensures long-term durability in demanding underhood environments.