Breaking 40 miles per gallon without burning diesel or relying on a hybrid drivetrain in a modern car isn't just difficult, it's damn near impossible. Volkswagen managed to do it, and not with a dinky econobox, but a full-size sedan.
The VW Passat BlueMotion Concept manages 42 mpg on the highway without an oil-burner or a hybrid system by taking a miserly 1.4-liter four-banger, slapping direct fuel injection and a turbocharger to boost output to 150 horsepower, and then adding something normally fitted to much larger engines: cylinder deactivation.
When the Passat is trundling along on the highway, two of the four cylinders are shut down, effectively turning the four-pot into an two-cylinder engine. As soon as the driver needs a bit more thrust and lays into the throttle, the other two cylinders get back in the action.
Volkswagen calls it Active Cylinder Management (ACT), and it's been available in Europe for a few years. And while VW is calling the Passat Bluemotion a "concept," it's likely to go on sale sometime next year after its debut at the Detroit Auto Show. Just don't expect a particularly impressive 0-60 mph time.
