First Drive: 2006 Mercedes-Benz C350
Burning Questions
Mercedes's new 3.2-liter CDI, a common-rail-injected turbodiesel V-6, boasts up to 376 pound-feet of torque when backed by Mercedes's class-leading seven-speed automatic. Goals for this new engine were increased horsepower, more torque, and reduced emissions. All were met. According to Mercedes-Benz, it's the world's first all-aluminum diesel V-6, which helps reduce weight, and its compact physical size makes the engine viable for numerous applications.
The CDI features dual overhead cams for each cylinder bank, a variable nozzle turbocharger (to maximize low-end torque), and piezo-electric injectors that provide ultra-precise fuel delivery. A balancer shaft between the cylinder banks greatly reduces second order vibrations in this 70-degree V-6. Unlike what you may expect from a diesel, this one runs clean enough to meet strict EU4 emissions standards without a diesel particulate filter--but still comes with one for some European markets.
Will Americans get to enjoy the benefits of this advanced, efficient powerplant? Yes, at least in one vehicle so far. By mid-2006, it'll replace the I-6 currently powering the E320 CDI sedan. Sometime thereafter, the CDI is likely to find its way into the new ML sport/utility which would be an ideal home for its torque and fuel-economy capabilities. But don't look for that combo until at least model year 2006. While evaluating the C350, we also had the chance to drive the C320 CDI, a terrific combination of compact sedan and super-torquey turbodiesel that, sad to say, isn't coming to the U.S. Maybe with increased market acceptance of diesel powertrains, Mercedes can be convinced to bring it here.