The 2012–2020 Subaru BRZ’s 2.0-liter flat-four engine is coded FA20.
The naturally aspirated FA20 was developed through Subaru and Toyota’s collaboration for the BRZ, Toyota 86 and Scion FR-S sports cars. It uses Subaru’s horizontally opposed four-cylinder layout and Toyota’s D-4S combination of direct and port fuel injection. In the BRZ, the engine produced about 200 horsepower in many markets, with output varying by transmission and model year.
The FA20 has an 86 mm bore and an 86 mm stroke, making it a “square” engine. That dimension also connects with the Toyota 86 name and helps explain the engine’s balanced reputation between revving ability and usable torque. The low, flat layout contributes to a low center of gravity, a central design goal of the BRZ.
The alternatives are common Subaru-engine mix-ups. EJ20 identifies an older performance-engine family, FB20 is a different Subaru boxer family, and 4G63 is a Mitsubishi four-cylinder. The turbocharged FA20F shares the FA20 family name but is not the naturally aspirated BRZ specification.