2006 sees Subaru claim the top prize in the 2-litre to 2.5-litre category at the International Engine of the Year Awards with the replacement for its popular 2-litre turbo unit. The triumph is Subaru’s first-ever Awards trophy, its previous best having been a runner-up placing in 2004.
The winning powerplant is a 2457cc four-cylinder DOHC housed in the Impreza and Forester, as well as the Saab 9-2X. With outputs of 227bhp and 277bhp (the latter when housed in the Impreza STi), the engine will power the standard Impreza to 100km/h (62mph) from a standstill in 5.4 seconds and onto a maximum speed of 229km/h (143mph).
The new 2.5-litre boxer offers more punch than the unit it replaces with maximum torque of 320Nm now being available 400rpm lower than previously, at 3,600rpm. Combined EU consumption figures remain impressive for an engine of this size and power, with 10.9L/100km (25.9mpg) for the STi, and 10.3L/100km (27.4mpg) for the less powerful vehicle.
Such alterations won over International Engine of the Year Awards judges the world over, enabling the 2.5 to topple last year’s winner, the 2.2-litre diesel from Honda. Giving his approval to the engine’s layout, Benoit Pérot commented: “A flat configuration is still the best for a compact and perfectly balanced four- cylinder engine.” Paul Weissler of Motor magazine in the US also is full of praise for the flat-four: “It may be a bad pun to talk about the ‘punch’ in this turbocharged ‘boxer’ engine, but the heart of our favourite ‘pocket rocket’ is also butter-smooth at idle."