Which Fuel System

Which Lethal Performance / DivisionX Fuel System Do I Choose?

Fuel systems aren’t sexy... but they are essential. Without proper fueling, your build is toast. DON’T SKIMP ON FUELING (seriously).

Need fast answers? Try our Fuel System Wizard below or jump straight to your Mustang's generation below. We also recommend reviewing our Fuel System FAQ and checking out our full DivisionX lineup.

Find Your Perfect Fuel System

Mustang Fuel System Information

Use the following info to help you decide which of our Mustang fuel systems fits your needs the best.

1999–2004 Mustang GT / Mach 1 / Cobra +

1999–2004 Mustang GT / Mach 1 / Cobra Fuel Systems

2V Budget System

2V Budget Return Style Fuel System

Applications: 1999–2004 Mustang GT

Horsepower: Up to 750 HP

Fuel Rails: No

Feed Line: Not included

Return Line: 6an

Notes: Requires level sender bracket or 03–04 Cobra sender

Install Guide

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4V Budget System

4V Budget Return Style Fuel System

Applications: 1999–2001 Cobra, 2003–2004 Cobra, 2003–2004 Mach 1

Horsepower: Up to 750 HP

Fuel Rails: No

Feed Line: Not included

Return Line: 6an

Notes: Level sender bracket required for accurate readings

Install Guide

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4V Budget Plus

4V Budget Plus Return Style Fuel System

Applications: 1999–2001 Cobra, 2003–2004 Cobra, 2003–2004 Mach 1

Horsepower: Up to 850 HP

Fuel Rails: No

Feed Line: 10an to Y-block, 8an to rails

Return Line: 8an

Notes: Higher flow; same fitment as standard Budget

Diagram

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Dual Pump System

Dual Pump Return Style Fuel System

Applications: 1999–2004 GT, Cobra, Mach 1

Horsepower: 850–1400 HP

Fuel Rails: Yes

Feed Line: 10an

Return Line: 8an

Notes: Sender bracket needed for GT/Mach 1

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Triple Pump System

Triple Pump Return Style Fuel System

Applications: 1999–2004 GT, Cobra, Mach 1

Horsepower: 1200–2000 HP

Fuel Rails: Yes

Feed Line: 10an

Return Line: 8an

Notes: Built for serious race/boosted builds

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2007–2014 Shelby GT500+

2007–2014 Shelby GT500 Fuel Systems

GT500 Deadhead Return System

GT500 Return Style Fuel System (Deadhead)

Applications: 2007–2014 Shelby GT500

Horsepower: Up to 2000 HP

Fuel Rails: Yes

Feed Line: 10an

Return Line: 6an

Notes: Level sender bracket required for 2010–2012 with OEM sender

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2010–2012 GT500 V2 Traditional

2010–2012 GT500 V2 Return Style (Traditional)

Applications: 2010–2012 Shelby GT500

Horsepower: Up to 2000 HP

Fuel Rails: Yes

Feed Line: 10an

Return Line: 8an

Notes: Uses post-rail regulator; sender bracket required with OEM sender

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2013–2014 GT500 V2 Traditional

2013–2014 GT500 V2 Return Style (Traditional)

Applications: 2013–2014 Shelby GT500

Horsepower: Up to 2000 HP

Fuel Rails: Yes

Feed Line: 10an

Return Line: 8an

Notes: Traditional regulator layout; plug-and-play for Whipple or turbo

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2011–2017 Mustang GT / Boss 302+

2011–2017 Mustang GT / Boss 302 Fuel Systems

Level 1 Fuel System

Level 1 Return Style Fuel System

Applications: 2011–2017 Mustang GT, 2012–2013 Boss 302

Horsepower: Up to 1000 HP

Fuel Rails: No

Feed Line: 8an

Return Line: 6an

Notes: Ideal for Whipple/Roush boosted street builds

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Level 2 Fuel System

Level 2 Return Style Fuel System

Applications: 2011–2017 Mustang GT, 2012–2013 Boss 302

Horsepower: Up to 1200+ HP

Fuel Rails: Yes

Feed Line: 8an

Return Line: 6an

Notes: Dual/triple pump support, flexible for big builds

Install Guide

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2015–2023 Mustang GT+

2015–2023 Mustang GT Fuel Systems

S550 Return Style Fuel System

S550 Return Style Fuel System

Applications: 2015–2017 Mustang GT

Horsepower: 850–2000 HP

Fuel Rails: Yes

Feed Line: 10an

Return Line: 8an

Notes: PTFE lines, modular pump options, Whipple/turbo ready

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2018+ Level 1 Fuel System

Level 1 Return Style Fuel System

Applications: 2018–2023 Mustang GT

Horsepower: Up to 1000 HP

Fuel Rails: Yes

Feed Line: 10an

Return Line: 8an

Notes: Gen 3 Coyote, stock manifold builds, pump gas or E85

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2018+ Return Style Fuel System

Return Style Fuel System

Applications: 2018–2023 Mustang GT

Horsepower: 800–2000+ HP

Fuel Rails: Yes

Feed Line: 10an

Return Line: 8an

Notes: Designed for Whipple/turbo Gen 3 Coyotes, flex fuel capable

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2024+ Mustang GT / Dark Horse+

2024+ Mustang GT / Dark Horse Fuel Systems

Level 1 2024+ System

Level 1 Return Style Fuel System

Applications: 2024+ Mustang GT / Dark Horse

Horsepower: Up to 1000 HP

Fuel Rails: Yes

Feed Line: 10an

Return Line: 8an

Notes: Designed for Gen 4 Coyote, stock manifold, pump gas or E85

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Full Return 2024+ System

Full Return Style Fuel System

Applications: 2024+ Mustang GT / Dark Horse

Horsepower: 800–2000+ HP

Fuel Rails: Yes

Feed Line: 10an

Return Line: 8an

Notes: Ideal for Whipple/turbo Gen 4 Coyotes, high-boost E85 setups

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Shelby GT350 / GT500 (2020+)+
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Shelby GT350 & 2020+ GT500 Fuel Systems

GT350 Fuel System

Shelby GT350 Fuel System

Applications: 2016–2020 Shelby GT350

Horsepower: Up to 1200 HP

Fuel Rails: Yes

Feed Line: 10an

Return Line: 8an

Notes: Built for high-RPM, high-boost Voodoo 5.2L applications

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2020+ GT500 Fuel System

2020+ GT500 Fuel System

Applications: 2020–2022 Shelby GT500

Horsepower: 800–1600+ HP

Fuel Rails: Yes

Feed Line: 10an

Return Line: 8an

Notes: Predator 5.2L ready, E85/race gas capable, plug-and-play

Install Guide

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Mustang Fuel System FAQ

What’s the difference between return and returnless fuel systems?

Returnless systems regulate fuel pressure in the tank. Return-style systems recirculate fuel and regulate pressure at the rails, improving consistency under boost and supporting high-output builds. All Lethal Performance systems are return-style conversions.

How do I choose the right fuel system for my Mustang?

Use our Fuel System Wizard to select your Mustang's year and power goals. You can also browse product cards above or contact us. Need a quick overview? 750 HP = Budget; 850–1200 HP = Dual pump; 1200+ HP = Triple pump.

What is a “deadhead” vs. “traditional” fuel system?

Deadhead systems regulate pressure before the rails. Traditional systems regulate pressure after the rails and return excess fuel to the tank. Traditional setups are often preferred for boosted or high-RPM builds.

Do I need new fuel rails?

Yes, especially for E85, boosted builds, or Gen 3+ Coyotes. DivisionX billet rails are included in most higher-power kits and support AN fittings and better flow.

What size feed and return lines should I run?

Up to 800 HP: 8an feed / 6an return. 800–1200 HP: 10an feed / 8an return. 1200+ HP or E85: dual 10an feed / 10an return recommended.

What are PTFE fuel lines and why are they used?

PTFE is ethanol-safe, heat-resistant, and leak-resistant. It's ideal for E85 and high-temp applications. Most DivisionX systems now include PTFE braided lines.

Can I run pump gas, race gas, or E85 with these systems?

Yes. All Lethal fuel systems are compatible with pump gas, race gas, and ethanol. Make sure your injectors and pumps are sized accordingly — E85 requires more volume.

What’s included in a complete Lethal/DivisionX fuel system?

Depending on power level: fuel hat, pumps, wiring, regulator, PTFE lines, fuel rails, Y-block, fittings, filters, and clamps — all pre-sized and ready to install.

Do I need a fuel pump voltage booster (BAP)?

Not with our return-style systems. High-output pumps are included. A BAP is only a bandaid for returnless systems or stock wiring limitations.

Do these systems support Flex Fuel or dual fuel maps?

Yes. All systems support flex fuel sensors and tuning with RTD4 or custom ECU maps. Just size injectors for your max fuel demand (especially on E85).

Where can I find install guides or wiring diagrams?

Each product card links to its install guide. You can also browse our full library of diagrams and instructions here:
Fuel System Installation Instructions