Subaru Turbo Parallel Hybrid

Leave it to Subaru to take a popular concept and tweak it just to be different. Famous for its horizontally opposed boxer engines, Subaru is now pioneering a new type of hybrid drivetrain that combines the company's 2.0L turbo EJ20 four-cylinder with a small electric motor and battery pack.

The engine has been modified to use the Miller Cycle, a technique that leaves the intake valves open during the beginning of the compression stroke to increase engine efficiency. Though normally coupled with a supercharger, like in the late Mazda Millenia, the Miller Cycle in Subaru's TPH relies on a turbo to "over-feed" the cylinders. The turbo's inherent lack of low-end torque is then compensated for by the output of the electric motor, thus creating a match made in heaven.

Continue reading for power and mileage ratings…

Power output is expected to be similar to that of the non-hybrid 2.0L turbo, or around 256 hp, while mileage is expected to increase from 30.6 mpg to 38.3 mpg. According to Subaru?s data, that would make its Legacy Hybrid more powerful and more fuel efficient than the Honda Accord Hybrid.