A through-the-road hybrid utilizes a completely independent electric motor that motivates only the rear axle. The system is less expensive than the parallel hybrid tech you’ll find in a Prius, for example, while still potentially providing a low-speed electric-only mode and regenerative braking.
Saab management reportedly told The Bureau that the turbocharged 2.8-liter V6 currently in use in the 9-5 would motivate the front wheels, while the electric motor and clutch assembly would work its magic out back. The new clutch assembly routes power to either of the rear wheels in a fraction of a second, helping the 9-3 stay on course regardless of the conditions. This setup will reportedly improve performance and agility, while negating the need to run a driveshaft from the engine to the rear axle. The end result is a simpler, lighter drivetrain, and we’re sure the overall gains in fuel economy won’t be to shabby, either.
[Source: The Detroit Bureau]
