Engine Subaru FB20

Engine Subaru FB20 under the hood

The FB20 engine has an AVCS variable valve timing system on the intake and outlet camshafts. The timing chain uses a maintenance-free chain. The engine is characterized by the installation of a plastic intake manifold with TGV flaps at the intake to improve environmental performance.

There are several modifications of this engine:

  • The FB20B has been produced in Japan since 2010 and is installed on such popular models as Forester, Impreza and XV. This motor is known for its impressive oil consumption from the first kilometers of run.
  • The FB20D was first introduced only in 2016 and replaced the FB20B engine under the hood of the popular Impreza and XV models. The new power unit highlights the presence of direct fuel injection instead of distributed.
  • The FB20X was produced by the Japanese concern from 2013 to 2017 and was installed on the hybrid versions of the Impreza and XV. Now this engine has given way to a similar unit with direct fuel injection.

The FB family also includes engines: FB16 and FB25.

The FB20B was installed on:

  • Subaru Forester 3 (SH) in 2010 – 2013;
  • Subaru Forester 4 (SJ) in 2012 – 2018;
  • Subaru Forester 5 (SK) since 2018;
  • Subaru Impreza 4 (GJ) in 2011 – 2016;
  • Subaru XV 1 (GP) in 2011 – 2017.

The FB20D was installed on:

  • Subaru Impreza 5 (GK) since 2016;
  • Subaru XV 2 (GT) since 2017.

The FB20X was installed on:

  • Subaru Impreza 4 (GJ) in 2015 – 2016;
  • Subaru XV 1 (GP) in 2013 – 2017.


Start of production 2010
Displacement, cc 1995
Fuel system distributed injection (FB20B)
direct injection (FB20D)
distributed injection (FB20X)
Power output, hp 148 – 150 (FB20B)
150 – 156 (FB20D)
162 (FB20X)
Torque output, Nm 196 (FB20B)
196 (FB20D)
221 (FB20X)
Cylinder block aluminum H4
Block head aluminum 16v
Cylinder bore, mm 84
Piston stroke, mm 90
Compression ratio 10.5 (FB20B)
12.5 (FB20D)
10.8 (FB20X)
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 (FB20B, FB20X)
4.9 (FB20D)
Fuel type petrol
Euro standards EURO 5/6
Fuel consumption, L/100 km (for Subaru Forester 2012)
— city
— highway
— combined
Engine lifespan, km ~250 000
Weight, kg 135 (FB20B)
140 (FB20D)
175 (FB20X)

Disadvantages of the FB20 engine

  • The most famous problem of this unit is oil consumption from the first kilometers;
  • It is necessary to use the recommended oil or the phase regulators will fail;
  • The engine is very afraid of overheating, monitor the condition of its cooling system;
  • The direct injection system made the FB20D very demanding on fuel quality;
  • Floating idle is usually caused by electronic throttle glitches.

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