The Subaru B5-TPH was a concept shooting-brake coupe with a Turbo Parallel Hybrid (TPH) powertrain made by Fuji Heavy Industries (FHI), introduced at the 2005 Tokyo Motor Show.

"[2] Contemporary news articles were generally supportive of the new design direction,[3][4] which anonymous sources claimed would be used in a forthcoming Impreza.

[3][6] The TPH drivetrain featured an electric motor-generator sandwiched between the gasoline motor, which used the Miller cycle, and the automatic transmission.

The electric motor was intended to reduce turbo lag and boost fuel economy, with an estimated consumption of 40 mpg‑US (5.9 L/100 km; 48 mpg‑imp) on the EPA combined city/highway cycle.

In the SSHEV design, the electric motor was used as the sole source of propulsion up to 80 km/h (50 mi/h), switching over to the gasoline engine above those speeds.