Fuel Hose Kit Buying Guide: Sizes, Fittings, and EFI Selection

Quick answer

Match the kit to four things before you buy: fuel type (pump gas, E85, or methanol), hose material (rubber, CPE, or PTFE), AN size (6AN, 8AN, or 10AN), and the exact fittings your pump module and fuel rail use. For most EFI builds on gasoline or E85, a CPE or PTFE kit in 8AN is the practical middle ground; step to 10AN only when flow and pump outlet size justify it.

A fuel hose kit is not a universal part. The right kit depends on what it connects: your pump module outlet, your filter, your fuel rail inlet, and the fuel you actually run. Buying by brand or price alone usually ends with adapters you did not plan for or a hose that softens with E85.

This guide walks through the decisions that matter most: hose material, AN size, fitting ends, and how to check fit before you order. It also covers when a complete plumbing kit makes more sense than assembling individual hose and fittings.

Start With Fuel Type, Not Brand

Fuel type is the first filter because it eliminates whole categories of hose. Standard rubber hose is fine for pump gasoline in a mostly stock system, but it degrades faster with ethanol blends and is a poor choice for E85 or methanol. CPE (chlorinated polyethylene) hose handles ethanol blends well and is a common choice for street-driven EFI builds. PTFE hose is the most chemically inert option and is the safer pick for methanol or aggressive fuels, though it typically costs more and requires different assembly technique.

If you are not sure what you will run long term, buy for the fuel you might run later. Replacing a hose kit because you switched to E85 costs more than choosing CPE or PTFE up front.

• Pump gasoline only: rubber or CPE both work; CPE lasts longer.
• E85 or flex fuel: choose CPE or PTFE.
• Methanol or race fuel: choose PTFE.
• Unknown future fuel: buy CPE or PTFE now to avoid a second purchase.

Pick AN Size From Flow and Pump Outlet

AN size is about flow area and matching your existing hardware. A 6AN hose is common on mild EFI setups and return lines; 8AN is the typical feed size for a single high-flow pump; 10AN shows up when a pump module has a large outlet or when the system is built for high horsepower. The hose size has to match the pump outlet and rail inlet, or you will be buying adapter fittings to bridge the gap.

Bigger is not automatically better. Oversized hose on a low-flow system adds cost, weight, and more places to leak without improving delivery. Size the feed line to the pump and the return line to the regulator, then keep both consistent.

• 6AN: mild EFI, return lines, and smaller pump outlets.
• 8AN: common single-pump feed size for street and track EFI.
• 10AN: large pump outlets and high-flow builds.
• Match hose size to pump outlet and rail inlet before ordering.

Fittings Decide Whether the Kit Actually Fits

Fitting ends are where most fuel hose kit purchases go wrong. You need to know whether each connection is a male AN flare, a hose barb, an OEM quick-connect, or a specific thread. A kit with the right hose and the wrong fitting ends still requires adapters, and every adapter is another potential leak point. Check the pump module, filter, and rail connections one by one and write down the type and size of each.

Angle also matters. Straight fittings work in open runs, but 45- and 90-degree fittings are often needed at the pump module or rail to clear chassis, tank, or intake components. If clearance is tight, plan the angles before you buy rather than after the hose is cut.

• List every connection: pump, filter, rail, regulator, return.
• Note thread type and size, not just AN size.
• Plan 45- or 90-degree fittings where clearance is tight.
• Fewer adapters means fewer leak points.

Complete Kits vs Individual Parts

A complete plumbing kit saves time when it is built for your exact vehicle and pump module. Vehicle-specific kits include the hose, fittings, and often the return line in one package, so you are not hunting individual part numbers. That convenience is worth it when the kit matches your chassis and pump, because the fitment work has already been done.

Individual hose and fittings make sense when your setup is custom, when you already have some components, or when you need a specific length or angle that a kit does not include. The tradeoff is more research and more chances to miss a fitting. If your build is mostly stock, a complete kit is usually the faster path.

• Choose a complete kit when it matches your vehicle and pump module.
• Choose individual parts for custom routing or partial upgrades.
• Verify kit contents against your connection list before ordering.
• Buy extra hose only if you are routing a non-standard path.

Installation and Routing Checks

Before installing, lay the hose out and confirm routing clears heat sources, moving suspension parts, and sharp edges. Fuel line heat shield is worth adding where hose runs close to exhaust or turbo components. Keep bends gentle, avoid kinks, and support the hose so it does not rub through over time.

On assembly, follow the fitting manufacturer's torque and lubrication guidance for the specific hose type. PTFE and CPE hose do not assemble the same way, and using the wrong method can damage the hose or leave a connection that weeps under pressure. Pressure-test the system before you consider the job finished.

• Route away from exhaust and moving parts.
• Add heat shielding where clearance is tight.
• Follow the fitting maker's assembly method for your hose type.
• Pressure-test before driving.

Decision rules for choosing a fuel hose kit

• Fuel type rule: Pump gasoline only: rubber or CPE. E85 or flex fuel: CPE or PTFE. Methanol or race fuel: PTFE. Pick the hose material for the fuel you will run, not just the fuel in the tank today.
• AN size rule: Match hose size to pump outlet and rail inlet. 6AN for mild EFI and returns, 8AN for typical single-pump feed, 10AN for large outlets and high flow. Do not oversize without a flow reason; it adds cost and leak points.
• Fitting rule: List every connection and confirm thread type, size, and angle before ordering. Add 45- or 90-degree fittings where clearance is tight. Every adapter you avoid is one less place to leak.
• Kit vs parts rule: Complete kit when it matches your vehicle and pump module; individual parts when routing is custom or you already own components. Verify kit contents against your connection list either way.
• Install rule: Route away from heat and moving parts, use heat shielding where needed, and follow the fitting maker's assembly method for your hose type. Pressure-test before driving.

Product facts that help the decision

• X2 Series Pump Module -8AN CPE Plumbing Kit for 2011-19 Ford Mustang: X2 Series Pump Module -8AN CPE Plumbing Kit for 2011-19 Ford Mustang A vehicle-specific 8AN CPE kit is a direct example of matching hose material and AN size to a known chassis and pump module, which removes most fitting guesswork for that application.
• X2 Series Pump Module 10AN PTFE Plumbing Kit for 2011-19 Ford Mustang: X2 Series Pump Module 10AN PTFE Plumbing Kit for 2011-19 Ford Mustang Shows the step up to 10AN and PTFE, which suits higher-flow setups and more aggressive fuels where chemical resistance and larger flow area matter.
• DW400 Install kit for S197 Mustang 5.0: DW400 install kit for Ford Mustang V6/GT 2011-14, Ford F-150 2009-14, Ford Raptor 2010-14 An install kit tied to specific vehicles illustrates why fitment lists matter more than hose length alone when you are matching a kit to a pump.
• 6AN to 3/8" Single Hose Barb: The DeatschWerks 6AN to 3/8" Single Hose Barb is an AN fitting designed to connect a 6AN male flare to a 3/8" single hose barb. It features a 90-degree configuration and an anodized matte black finish. A single adapter like this is often the difference between a kit that fits and one that does not, especially when a 90-degree bend is needed to clear chassis or tank components.

Who this approach fits

Best for

• Street and track EFI builds running pump gas or E85 with a single high-flow pump.
• Owners of supported chassis who want a vehicle-specific plumbing kit instead of piecing together hose and fittings.
• Builders who need to match an existing pump module outlet and fuel rail inlet without guessing.

Not for

• Carbureted systems, which use different hose and fitting conventions.
• Fully custom chassis where no vehicle-specific kit exists and every line must be fabricated.
• Methanol-only race builds that should go straight to PTFE without considering rubber or CPE.

Choose the hose material for your fuel, the AN size for your flow and pump outlet, and the fittings for your actual connections. If a vehicle-specific kit matches your chassis and pump module, it usually saves time and avoids adapter guesswork. If not, build the connection list first and buy hose and fittings to match it.