Since 2010, the company’s plant has assembled the 2.5-liter Subaru FB25B gasoline engine, which is fitted to the company’s mid-size models, including the Legacy and Forester. In 2018, the unit underwent an upgrade that switched from multipoint fuel injection to direct.
The FB16 and FB20 internal combustion engines are also members of the FB family.
The engine was mounted on:
- Subaru Forester 2 in 2010 – 2013;
- Subaru Forester 3 (SH) in 2012 – 2018;
- Subaru Forester 4 (SJ) since 2018;
- Subaru Legacy 5 (BM) in 2012 – 2015;
- Subaru Legacy 6 (BN) in 2014 – 2019;
- Subaru Legacy 7 (BW) since 2019;
- Subaru Exiga 1 (YA) in 2012 – 2015.
Specifications
| Production years | since 2010 |
| Displacement, cc | 2498 |
| Fuel system | distributed injection (until 2018) direct injection (after 2018) |
| Power output, hp | 172 – 175 (until 2018) 185 (after 2018) |
| Torque output, Nm | 235 (until 2018) 240 (after 2018) |
| Cylinder block | aluminum H4 |
| Block head | aluminum 16v |
| Cylinder bore, mm | 94 |
| Piston stroke, mm | 90 |
| Compression ratio | 10 – 10.3 (until 2018) 12.0 (after 2018) |
| Features | DOHC |
| Hydraulic lifters | no |
| Timing drive | chain |
| Phase regulator | Dual AVCS |
| Turbocharging | no |
| Recommended engine oil | 0W-20 |
| Engine oil capacity, liter | 4.8 |
| Fuel type | petrol |
| Euro standards | EURO 5 (until 2018) EURO 6 (after 2018) |
| Fuel consumption, L/100 km (for Subaru Legacy 2017) — city — highway — combined |
10.1 6.2 7.7 |
| Engine lifespan, km | ~250 000 |
| Weight, kg | 150 |
Disadvantages of the FB25 engine
This engine, in contrast to its 2-liter counterparts, is not renowned for its high oil consumption; however, the phase regulators will fail if the lubricant is of poor quality.
The engine is terrified of overheating, and the cooling system is unreliable;
Floating speed is caused by issues with the electronic throttle’s operation;
The motor may start to make noise and knock even with a small decrease in lubrication.