The 2009 Forester offered two engine choices: a 2.5-liter naturally aspirated boxer-four and, in the XT trim, a 2.0-liter turbocharged boxer-four. Both are part of Subaru’s signature flat-4 “boxer” engine family.
In the following, you’ll find a concise breakdown of the two engines, what sets them apart, and how they were deployed across the 2009 Forester lineup. This overview reflects the commonly available configurations in the United States for that model year.
Engine options in the 2009 Forester
The two primary engine configurations can be summarized as follows:
- 2.5-liter horizontally opposed four-cylinder (boxer) engine — Naturally aspirated, typically producing about 170 horsepower and around 170 lb-ft of torque. This engine uses dual overhead camshafts (DOHC) and multi-point fuel injection, and it’s used in the base and mid-range Forester models.
- 2.0-liter turbocharged horizontally opposed four-cylinder — Turbocharged, delivering roughly 224 horsepower and about 226 lb-ft of torque. Found in the Forester XT, this engine adds a turbocharger and intercooler for higher performance and stronger midrange response.
In summary, buyers could choose between the efficient, naturally aspirated 2.5L and the performance-oriented 2.0L turbo in the XT. The choice influenced acceleration, power delivery, and overall driving character of the vehicle.
Standard 2.5-liter engine
The standard engine for most 2009 Forester models is a 2.5-liter flat-four (boxer) engine. It features DOHC and multi-point fuel injection, with output around 170 hp and roughly 170 lb-ft of torque depending on the exact revision and market. This setup emphasizes smooth operation, balanced fuel economy, and reliable everyday performance, with some trims benefiting from variable valve timing on the intake side to improve low- and mid-range response.
2.0-liter turbocharged engine (XT)
The Forester XT variant is equipped with a 2.0-liter turbocharged boxer engine. The turbocharger boosts power to around 224 hp and about 226 lb-ft of torque, delivering quicker acceleration and a stronger midrange compared with the naturally aspirated model. As a turbocharged engine, it also emphasizes a more engaged driving feel, especially in boost-rich conditions, and was paired with transmissions offered across the 2009 Forester lineup depending on region.
Maintenance and technical notes
Both engines belong to Subaru’s broader family of horizontally opposed "boxer" engines, known for a lower center of gravity and smooth operation. When evaluating a used 2009 Forester, consider typical maintenance items such as timing-related service intervals, oil quality, and cooling system health, as with most age-bracketed vehicles. Always verify the specific engine and trim configuration for a given vehicle, as options could vary by market and production date.
Summary
The 2009 Subaru Forester offered two engine configurations: a 2.5-liter naturally aspirated boxer-four for standard models and a 2.0-liter turbocharged boxer-four for the XT, delivering notably more power. Both engines share Subaru’s signature flat-4 design, delivering distinct driving characteristics—economy and smoothness from the 2.5L, and stronger performance from the 2.0L turbo.