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.
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 |
The engine was installed on:
- Subaru Forester 2 in 2010 – 2013, Forester 3 (SH) in 2012 – 2018, Forester 4 (SJ) since 2018;
- Subaru Legacy 5 (BM) in 2012 – 2015, Legacy 6 (BN) in 2014 – 2019, Legacy 7 (BW) since 2019;
- Subaru Exiga 1 (YA) in 2012 – 2015.
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.
Frequently asked questions about the Subaru FB25
How much power does the Subaru FB25 make?
Power output of the Subaru FB25, hp: 172 - 175 (until 2018); 185 (after 2018). Torque, Nm: 235 (until 2018); 240 (after 2018).
How much oil does the Subaru FB25 take and which one?
Engine oil capacity: 4.8 liters. Recommended oil: 0W-20.
Does the Subaru FB25 have a timing belt or chain?
The Subaru FB25 uses a timing chain.
Is the Subaru FB25 turbocharged?
No, the Subaru FB25 is naturally aspirated.
Does the Subaru FB25 need valve clearance adjustment?
Yes, there are no hydraulic lifters, so the valve clearances have to be checked and adjusted periodically.
How long does the Subaru FB25 last?
The typical lifespan of the Subaru FB25 is ~250 000 km with proper maintenance.
What is the fuel consumption of the Subaru FB25?
Subaru Legacy 2017: city 10.1, highway 6.2, combined 7.7 L/100 km.
What cars was the Subaru FB25 installed on?
Subaru Forester 2 in 2010 - 2013, Forester 3 (SH) in 2012 - 2018, Forester 4 (SJ) since 2018; Subaru Legacy 5 (BM) in 2012 - 2015, Legacy 6 (BN) in 2014 - 2019, Legacy 7 (BW) since 2019; Subaru Exiga 1 (YA) in 2012 - 2015.
What are the common problems of the Subaru FB25?
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. All known problems.
