Engine Subaru EJ25

The EJ25 engine, which had a displacement of 2.5 liters, was released by Subaru in 1994. This engine block was identical to the EJ20 engine block – it was made of aluminum alloy and had a height of 201 mm. The only difference was in the cylinder diameter – unlike the 2.0-liter engine, which had 92 mm, the 2.5-liter engine had 99.5 mm.

  • The EJ25D was produced by the company from 1994 to 1999 and was installed on almost all mass models of the concern in the mid-90s of the last century. This motor served as the basis for the creation of a whole series of units, including those with turbocharging.
  • The EJ251 was produced from 1998 to 2004 and was installed on almost the entire model range of the concern at that time: Impreza, Legacy and Forester. For markets with strict environmental requirements, a version with the EJ252 index was offered.
  • The EJ253 was produced from 1999 to 2012 and was installed on the Impreza, Legacy and Forester and other models. The motor differed from its predecessors by the presence of a mass air flow sensor instead of an absolute pressure sensor and an i-AVLS phase regulator.
  • The EJ254 was produced from 1998 to 2007 and is most often found on the third generation Legacy, but it was also installed on the Forester and Outback. It was this unit that was one of the first to be equipped with the proprietary AVCS phase control system.
  • The EJ255 has been produced since 2004 and is installed on charged versions of such popular models as the Impreza, Legacy and Forester. This power unit has many different modifications with power from 210 to 265 hp.
  • The EJ257 has been produced since 2004 and is primarily known for a series of sports modifications of the Impreza model with the WRX STI index. This motor in a less forced form was installed on charged versions of the Forester and Legacy.


Start of production 1994
Displacement, cc 2457
Fuel system injector
Power output, hp 155 – 165 (EJ25D)
165 (EJ251)
165 (EJ253 without phase control system)
175 (EJ253 with phase control system)
165 – 170 (EJ254)
210 – 265 (EJ255)
210 – 250 (EJ257 basic)
280 – 310 (EJ257 STI)
Torque output, Nm 190 – 220 (EJ25D)
225 (EJ251)
225 (EJ253 without phase control system)
225 – 230 (EJ253 with phase control system)
240 – 245 (EJ254)
320 – 350 (EJ255)
320 – 350 (EJ257 basic)
390 – 410 (EJ257 STI)
Cylinder block aluminum H4
Block head aluminum 16v
Cylinder bore, mm 99.5
Piston stroke, mm 79
Compression ratio 9.5 (EJ25D)
10 (EJ251, EJ253)
10.2 – 10.7 (EJ254)
8.2 – 8.4 (EJ255)
8.4 (EJ257 basic)
8.0 – 8.2 (EJ257 STI)
Features DOHC (EJ25D, EJ254, EJ255, EJ257)
SOHC (EJ251, EJ253)
Hydraulic lifters no
Timing drive belt
Phase regulator no (EJ25D, EJ251, EJ253 without phase control system)
i-AVLS (EJ253 with phase control system)
AVCS (EJ254, EJ255, EJ257)
Turbocharging no (EJ25D, EJ251, EJ253, EJ254)
yes (EJ255, EJ257)
Recommended engine oil 5W-30
Engine oil capacity, liter 4.0 (EJ25D)
4.2 (EJ251, EJ253, EJ255, EJ257 basic)
4.6 (EJ254)
4.3 (EJ257 STI)
Fuel type petrol
Euro standards EURO 1/2 (EJ25D)
EURO 2/3 (EJ251, EJ253 without phase control system)
EURO 3/4 (EJ253 with phase control system, EJ254, EJ255, EJ257)
Fuel consumption, L/100 km (EJ25D for Subaru Legacy 1997)
— city
— highway
— combined
Engine lifespan, km ~300 000
Weight, kg 130 (EJ25D, EJ251)
135 (EJ253, EJ254)
170 (EJ255)
175 (EJ257)

Disadvantages of the EJ25 engine

  • The main complaints of car owners with such an engine are related to oil consumption;
  • Moreover, the oil is consumed not only for waste, but oozes from gaskets and seals;
  • If you miss too low a level of lubrication, then the liners can turn;
  • This motor is quite hot and the cooling system is not known for being efficient;
  • The fact that as a result of overheating led the block you will know by the knocks of the 4th cylinder.

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