The 2.5-liter Subaru FB25B gasoline engine has been assembled at the company’s plant since 2010 and is installed on mid-size models of the concern, such as Legacy and Forester. The unit was upgraded in 2018 and changed from multipoint fuel injection to direct.
The FB family also includes internal combustion engines: FB16 and FB20.
The engine was installed 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
- Unlike the 2-liter counterparts, this engine is not famous for its strong oil consumption;
- But it is also demanding on the quality of the lubricant, otherwise the phase regulators will fail;
- The cooling system is not very reliable, and the engine is extremely afraid of overheating;
- Malfunctions in the operation of the electronic throttle lead to floating speed;
- Even with a slight drop in the level of lubrication, the motor may begin to make noise and knock.
