Using E85 Ethanol Fuel in the 2022 Subaru WRX FA24 Turbo Engine

Introduction to E85 and the 2022 WRX

The 2022 WRX from Subaru features a turbocharged 2.4-liter 4-cylinder engine that, like many modern performance vehicles, is designed to operate on premium 91 or 93 octane gasoline. However, some owners may be interested in using an alternative biofuel called E85 that combines 85% ethanol with 15% gasoline.

What is E85?

E85 refers to fuel that contains 51% to 83% ethanol blended with gasoline and other additives. Ethanol is ethyl alcohol derived from corn and other plant materials that serves as a renewable fuel alternative to pure gasoline.

Compared to standard pump gasoline, E85 has a number of properties that can benefit high-performance engines like the one found in the 2022 WRX. These properties allow engine calibrators to take advantage of E85’s fuel qualities to produce more power.

Benefits of Using E85 in the 2022 WRX

Running the FA24 engine with E85 offers several potential advantages:

• Higher octane rating – E85 can have octane ratings over 100 vs 91/93 for premium gasoline
• Cools the intake air charge thanks to ethanol’s latent heat vaporization
• Allows for more aggressive ignition timing and turbo boost
• Burns cleaner while producing less greenhouse gases

By taking advantage of these characteristics and reprogramming aspects like fuel injection, ignition timing, and boost control, significant horsepower and torque gains of 15% or more are possible on modified engines.

Considerations When Using E85 in the 2022 WRX

While E85 has performance benefits, it also comes with some downsides and special equipment considerations when used in the 2022 WRX.

Cold Startability

Since ethanol is harder to vaporize than gasoline, using E85 can make cold engine starts more difficult, especially in winter. Modifications like upgraded fuel pumps and injectors combined with an E85 sensor and custom tuning can help mitigate these issues.

Fuel System Upgrades

The 2022 WRX fuel system components were designed with standard gasoline in mind. To run E85 properly and safely, upgraded fuel pumps and fuel injectors provides the extra fuel flow and delivery capacity needed for maximum power.

Fuel Economy Reduction

While power potential increases, fuel economy tends to decrease by about 15-25% when running E85 since more fuel is required to maintain an optimal air/fuel ratio. This may be offset by ethanol's lower current price compared to gasoline.

E85 Availability

Unlike gasoline, public E85 availability is still limited in most areas, so ensuring convenient access is an important consideration before converting a car to use it.

Making the 2022 WRX E85-Compatible

Properly converting a standard FA24 to use E85 requires several fuel system modifications along with custom ECU tuning to yield the best performance and drivability.

Fuel System Upgrades

Here are typical hardware upgrades needed to run E85 in a 2022 WRX:

• Replace the factory fuel pump with a higher-flowing in-tank pump
• Install larger fuel injectors (1200cc or larger)
• Add an E85 flex fuel content sensor
• Consider upgraded fuel lines and fuel rails

Engine Management Tuning

The Subaru’s factory ECU calibration is designed for premium pump gas use only. To properly account for E85’s different fuel properties, an aftermarket ECU tune on an accessport or standalone engine management system is required. This allows adjusting parameters like:

• Increasing overall fuel delivery
• Adjusting injector flow rate and performance tables
• Retarding ignition timing to control knock
• Altering boost control logic
• Recalibrating throttle response
• Optimizing cold start settings

Professional tuners with experience calibrating high-performance Subarus for E85 blends can provide the programming expertise needed to maximize horsepower gains while retaining streetable drivability in the 2022 WRX.

Getting the Most from E85 in the 2022 WRX

The 4-cylinder turbo engine in the latest WRX responds very well to upgraded fuel delivery and timing adjustments to take advantage of E85's performance potential. Here are some additional tips for maximizing benefits after converting to use it as an alternative fuel.

Adjust for Ambient Conditions

Since ethanol is sensitive to ambient temperature changes, consider using an E85 content sensor. This allows the ECU to automatically compensate if the ethanol percentage changes with seasonal fuel blends.

Upgrade Other Systems

If pushing substantially more power with E85, consider upgrades like an intercooler, free-flowing exhaust, and engine internals so other systems don't limit output.

Improve Daily Drivability

A properly optimized street tune focuses on enhancing power across the full RPM range rather than peak dyno numbers alone. This improves daily and real world acceleration.

Frequently Check Fuel Components

Make sure all fuel system upgrades are thoroughly vetted and monitored. Aggressive E85 tunes can be demanding, so inspect lines, pumps, seals routinely to avoid problems from potential leaks or failures.

By combining purpose-built ethanol fuel hardware with professional ECU calibration, the 2022 Subaru WRX's turbo engine responds beautifully to E85, providing owners with substantially better performance and enjoyment.

FAQs

What kind of horsepower gains can I expect when using E85 in my 2022 WRX?

With supporting fuel system upgrades and ECU tuning, 15-30% horsepower gains over 93 octane pump gas are common when using E85. However results can vary depending on modifications.

Do I need a custom tune to run E85 fuel in my FA24 engine?

Yes, the factory ECU calibration is designed for premium 91/93 octane gasoline only. Proper use of E85 requires flashing an aftermarket tune file optimized specifically for use with ethanol content.

What fuel system upgrades does my 2022 WRX need to properly run E85 fuel?

Typical E85 conversion hardware includes installing upgraded fuel pumps, higher flow fuel injectors, an ethanol content sensor, and possibly fuel line and rail upgrades. The fuel system needs to support more flow.

Will using E85 fuel hurt my engine or void my car's factory warranty?

When combined with suitable fnardware and professional tuning, E85 use does not directly increase the chance of engine damage compared to gasoline. However, altering the vehicle from factory form can impact warranty coverage.