The WRX and WRX STI share a body and all-wheel drive, but the STI was the harder-edged model: a 2.5-liter EJ257 turbo engine, a six-speed manual only, a driver-controlled center differential, bigger brakes and stiffer suspension. The 2015 to 2021 WRX used the 2.0-liter direct-injection FA20 turbo at 268 hp, while the STI made about 305 to 310 hp. The STI ended after the 2021 model year in the US; the current WRX uses the 2.4-liter FA24 at 271 hp.
WRX vs STI specs (2015 to 2021)
| WRX | WRX STI | |
|---|---|---|
| Engine | 2.0L FA20 direct-injection turbo | 2.5L EJ257 turbo |
| Rating | 268 hp | About 305 to 310 hp, depending on year |
| Transmission | Six-speed manual or CVT | Six-speed manual only |
| All-wheel drive | Viscous or electronically controlled center | Driver-controlled center differential (DCCD) |
| Brakes and suspension | Standard | Larger brakes, stiffer setup, wider wheels |
WRX vs STI engines
The EJ257 is an older port-injected design with a reputation for strength when stock and for ringland and head gasket problems when pushed hard; see EJ257 problems and Subaru head gasket and ringland failures. The FA20 is newer and more fuel-efficient, with direct injection and a twin-scroll turbo. See EJ255 vs EJ257 and FA20 vs FA24.
Reliability
Both cars are durable when maintained and driven within their limits. The STI’s EJ257 needs careful warm-up and oil level checks, and many owners watch for ringland failure on modified cars. The FA20 benefits from regular oil changes and attention to oil consumption. Engine health matters more than the badge when buying used.
Driving differences
The STI’s driver-controlled center differential lets the driver shift torque between the axles, and its quicker steering and stiffer suspension make it sharper on a track but harsher on rough roads. The WRX rides more comfortably and, with the FA20’s lower-rpm torque, feels quicker in everyday driving than its power figure suggests. Fuel economy also favors the WRX.
Used prices and what to look for
STIs hold their value well, so a used STI usually costs more than a WRX of the same year. On either car, look for signs of hard use, aftermarket engine changes without records, and clutch wear; see signs of a bad clutch.
Which is right for you?
- Daily driving and fuel economy: WRX.
- Track use and a manual-only, more mechanical car: STI.
- Newest model: the 2022 and later WRX with the FA24, since the STI ended after 2021.
Parts differences
Many exhausts and lighting parts fit both sedans of the same years, while engines, clutches and turbos are model-specific. Our cat-backs for the 2011 to 2021 WRX and STI sedans are listed on WRX exhaust, and parts by platform on Subaru WRX and STI parts. Replacement EJ25 engines are on Subaru EJ25 engines, and generations are explained in WRX generations.
More guides: FA20 problems · EJ25 problems · how long a WRX engine lasts · EJ257 specs · FA20 specs · front mount vs top mount intercooler.
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