2025 Subaru Crosstrek

Boxer

2.0L Flat-4

A horizontally-opposed four whose pistons punch out sideways, giving it a low, planted center of gravity and that distinctive thrummy, off-beat idle Subaru fans know by ear. Power delivery is modest but linear, tuned for broad, usable torque rather than top-end drama.

The FB-series boxer is Subaru's third-generation flat-four, announced in 2010 to replace the long-running EJ engine; Subaru has built horizontally-opposed engines continuously since the EA-series of 1966. It is one of only two automakers to persist with boxer engines for mainstream cars.

• Subaru internally jokes that 'FB' stands for 'Future and Brand-new Boxer.'
• Versus the older EJ, the FB was redesigned with a longer stroke and narrower bore to broaden torque and cut emissions.
• Porsche is the only other major automaker that still builds boxer engines for road cars.