Fuel Lines, Hose & Hard Line Kits

Fuel Lines, Hose & Hard Line Kits

Fuel lines are the arterial system of any EFI or carbureted fuel setup, and choosing the right material, diameter, and pressure rating for your application determines both safety and long-term system reliability. Rubber fuel hose, while acceptable for low-pressure carbureted applications, degrades when exposed to modern ethanol-blended fuels and can collapse internally under the vacuum of a high-flow fuel pump, restricting fuel delivery in ways that are nearly impossible to diagnose without cutting the hose open. Stainless steel braided PTFE-lined hose is the upgrade standard for any EFI or boosted application, offering rated burst pressures above 1,000 PSI, full ethanol and methanol compatibility, and resistance to heat soak in engine bay routing. Custom hard line fabrication with stainless or aluminum tubing is also popular for clean engine bay builds and chassis routing where flex hose is impractical.

Popular Upgrades

Top-selling fuel line products include Earl's Pro-Lite 350 stainless braided hose in AN-6 and AN-8 for EFI supply and return circuits, Aeromotive stainless-over-PTFE hose for high-pressure EFI and direct injection systems, and Fuelab pre-bent stainless hard line kits for popular truck and muscle car chassis. Fragola Series 3000 hose in cut-to-length spools is a go-to choice for fabricators building custom fuel systems in street rods and restomod builds. For quick connector conversions on factory vehicles, Dorman hard line repair sections with push-lock fittings allow precise length matching without a full custom fabrication.

Performance and Handling

At sustained fuel pressures above 60 PSI in direct-injection systems, only PTFE-lined stainless braided hose maintains safe burst margin with the flexibility needed for routing around chassis and engine components. Standard rubber fuel hose not rated for EFI pressures will balloon internally over time, reducing effective inner diameter and causing fuel starvation at high demand. In chassis routing where the fuel line passes near hot exhaust components, using a fire-sleeve or ceramic heat shield wrap over the hose protects the outer braid from heat exposure that can cause stress cracking on the stainless weave.

What size fuel line do I need for my EFI performance build?

AN-6 line, equivalent to 3/8-inch inner diameter, is the standard supply line size for naturally aspirated engines up to approximately 500 horsepower at normal fuel pressure. AN-8 supply line, equivalent to 1/2-inch inner diameter, is the correct choice for turbocharged and supercharged builds above 500 horsepower or any application running a return-style system with a high-flow pump. AN-6 return lines are adequate for most return-style systems since the return circuit operates at low pressure and flows only the excess fuel bypassed by the pressure regulator.

Can I use push-lock fittings instead of AN swivel fittings for fuel lines?

Push-lock fittings rated for fuel use are acceptable for low-pressure carbureted systems and garage shop connections but are not recommended for sustained EFI pressures above 15 PSI since the barb retention relies on hose material compression rather than a mechanical lock. AN swivel end fittings with a proper hose socket crimped or assembled over the hose braid provide a positive mechanical connection that maintains rated pressure even when the hose is fully pressurized and temperature-soaked. In any application where the fuel line cannot be visually inspected regularly, AN swivel fittings are the only appropriate choice for long-term reliability.

Why These Parts Fit Right

Every fuel line and hose product in this collection is listed with pressure rating, inner diameter, compatible fittings, and fuel compatibility so you can build your system with complete information. Sold in cut-to-length spools, pre-built lines, and complete kits to suit both custom fabrication and bolt-on applications. Orders ship from US warehouses with fast turnaround to keep your build moving forward.

Complete your fuel system build with high-flow air intake systems, add performance with custom exhaust systems, and support your chassis with suspension upgrades matched to your power level.