The concept editions--a C30, S40, and V50--use an existing 1.6-liter turbodiesel four and pair it with aero tricks, special Michelin tires with low rolling resistance, taller gearing, and other drivetrain enhancements to help the cars eke out lower emissions and greater mileage.
Specifically, the trio emits 115 g/km (C30) and 118 g/km (S40 and V50) and earn 76 mpg in Europe's combined cycle. Yeah, yeah, yet another European diesel fuel sipper that blows away the Toyota Prius in mpg figures (even after adjusted for U.S. EPA consumption figures, which compute a bit lower).
Despite the Parisian tease, Volvo has no plans for diesel in the North American market. Subaru just released a splendid boxer turbo diesel in Paris (more teasing, ooh-la-la), but is letting other automakers take the diesel gamble in North America before it makes a move. BMW and Mercedes are fighting the diesel fight with killer performance (BMW 335d, Mercedes E320 BlueTEC), and it seems that only VW is trying the ultra-efficiency route with its Jetta TDI Clean Diesel.
Source: Volvo via Autoblog