2005 Subaru B5-TPH Concept

The Subaru B5-TPH is a sleek coupe-wagon-crossover concept that Subaru made clear is not the next Subaru Impreza. While Subaru positioned the car as a technology showcase rather than a design statement, the B5-TPH ended up being one of the brand’s best-looking concepts in years. It sits on a modified Subaru Legacy platform and pairs sharp styling with raised ride height and all-wheel drive.

The real focus is Subaru’s Turbo Parallel Hybrid (TPH) system, which combines a turbocharged 2.0-liter flat-four boxer engine with a thin electric motor mounted between the engine and automatic transmission. The engine uses Miller-cycle technology—last seen in cars like the Mazda Millenia—to improve efficiency by reducing pumping losses. Normally, this hurts low-speed response, but Subaru says the electric motor fills in torque at launch, delivering better standing-start performance than even the Subaru Impreza WRX.

The hybrid system produces a combined 256 hp and 253 lb-ft of torque. A compact lithium-ion manganese battery—lighter, longer-lasting, and cheaper than nickel-metal hydride—powers the electric assist. While the motor output is modest, it reduces turbo lag, improves throttle response, and helps cut fuel consumption by roughly 30 percent.

Visually, the pearl-white concept featured 200 mm of ground clearance, symmetrical all-wheel drive, and a dramatic glass rear hatch that lifted like a clamshell. Chief designer Andreas Zapatinas denied the B5-TPH was a preview of the next Impreza but left the door open for a future three-door hatchback inspired by its proportions.

Subaru said the exact car wouldn’t reach production, but variations of the TPH system were likely—potentially appearing in models like the Subaru Forester—as early as 2007.