Racing Fuel Cell & Accessories

A auxiliary fuel cell is a purpose-built fuel storage unit designed for performance, racing, off-road, or custom-build applications, while a factory fuel tank is a stamped-steel or molded-plastic part designed for one specific vehicle model and daily commuting.

Key differences:

• Construction: Fuel cells are typically made from aluminum, steel, or high-strength composite, giving them higher burst/impact strength than a factory tank.
• Fit: Fuel cells are usually "universal fit" — you mount them into custom locations (trunk, bed, chassis bay), whereas a factory tank is molded to fit one specific vehicle.
• Internal features: Many fuel cells include anti-slosh foam to reduce fuel movement and vapor buildup, plus a fill plate, vents, and mounting flange designed for aftermarket fuel systems.
• True racing/competition fuel cells (SFI/FIA-certified) also include a flexible internal bladder that absorbs impact and helps contain fuel in a crash — this is what separates a certified "safety fuel cell" from a simple aluminum tank.

For the right use case, yes. An auxiliary tank is worth it if you regularly deal with:

• Long-distance driving or towing, where stock fuel range isn't enough between stops
• Off-road, overlanding, or remote-area travel, where fuel stations are far apart or nonexistent
• Work trucks covering large routes or job sites where downtime for refueling costs money
• Fuel price flexibility — carrying extra fuel lets you fill up where prices are lower instead of wherever you happen to be running low

It's less worth it if you mostly drive short, local trips with easy access to gas stations — in that case, the added weight, reduced bed space, and installation cost may outweigh the benefit.

Before buying auxiliary fuel tank, confirm capacity needs (how many extra miles you actually need), whether your fuel type requires a pump-fed or gravity-fed setup, and whether the kit includes the fittings, lines, and level sender you'll need for a clean install.

Lifespan depends on the type of fuel cell:

• SFI/FIA-certified competition bladder cells have a defined service life because the bladder material itself ages. SFI Spec 28.3 (Competition Fuel Cell Bladder) requires recertification every 5 years, and FIA FT3-certified bladders carry a 5-year validity from the date of manufacture (some manufacturers offer a short recertification extension if requested before expiration). After that, the bladder must be inspected, recertified, or replaced — this is a safety requirement, not just a suggestion, for sanctioned racing.
• Solid aluminum fuel cells (no bladder) — like EVIL ENERGY's fuel cell gas tanks — don't have a bladder aging clock, so the tank body itself can last many years of service under normal conditions. The parts that do wear over time are the anti-slosh foam (which should be inspected periodically and replaced if it degrades or compacts) and the level sender and fittings/seals, which are wear items on any fuel system.

Practical takeaway: for a street/drift/drag/off-road build, a well-maintained aluminum fuel cell can outlast several seasons of use; for sanctioned competition requiring SFI/FIA certification, plan on a bladder recertification or replacement roughly every 5 years regardless of how much you've used it.

Yes. But material compatibility is the deciding factor, not just the tank itself.

E85 (85% ethanol) is not corrosive to metal on its own, but it is hygroscopic — it absorbs water readily, and water-contaminated ethanol can form mild organic acids that attack unprotected aluminum, zinc, brass, and copper over time. It also degrades some rubber and standard nylon fuel line materials.

What this means for your setup:

• Tank body: Aluminum fuel cells are generally fine with E85 as long as fittings/hardware are corrosion-resistant (anodized or stainless where possible) and the tank is kept full or empty (not partially full) during long-term storage to reduce condensation.
• Fuel lines matter as much as the tank: EVIL ENERGY fuel cell kits are E85/ethanol/methanol compatible when paired with PTFE fuel line — PTFE resists ethanol degradation. CPE (rubber-based) fuel line is not recommended with E85, methanol, or high-ethanol blends, as it can swell, degrade, or leak over time.
• Competition bladder cells: If you're running a true SFI/FIA-certified bladder fuel cell, confirm with the manufacturer that the bladder compound is rated for high-ethanol fuel — not all bladder materials are E85-safe, even if they're fine with pump gasoline.

EVIL ENERGY's PTFE-line fuel cell kits are built with E85 compatibility in mind — see the E85-compatible Fuel Cell Kits.

At a basic level, a fuel tank/fuel cell exists to:

• Store fuel safely and protect it from dirt, moisture, and vapor loss
• Support consistent fuel delivery to the engine at the correct pressure, even under acceleration, braking, or high-G cornering
• Work with the vehicle's emissions system (on factory tanks) to control fuel vapor
• Prevent leaks and fire risk in the event of an impact — this is the primary reason racing fuel cells exist

Beyond daily driving, fuel cells specifically are used for:

• Racing and motorsports (drag, drift, circuit, off-road/baja)
• Engine swaps where the stock tank no longer fits or flows correctly (e.g., LS swaps)
• Auxiliary/extended-range fuel storage for trucks and overland builds
• Custom and show vehicle builds where tank shape/size needs to be non-stock