The BlueTEC 3.0-L V6 from Mercedes-Benz is continuing to bring diesel technology into the future. As installed in the 2010 GL350, the engine features the company's BlueTEC exhaust aftertreatment technology based on selective catalytic reduction. The system uses the urea-based reductant AdBlue for effective reduction of NOx, making the SUV compliant with stringent U.S. Tier 2 NOx emissions regulations. The engine's common-rail direct fuel-injection system features piezo-type injector technology. Paired with the 7G-TRONIC seven-speed automatic gearbox, the diesel allows for a high level of performance with reduced environmental impact, claims Mercedes.