Mercedes-Benz BlueTEC passenger cars have been on the cutting edge of clean diesel technology since 2006. These BlueTEC vehicles furthermore passed millions of kilometers in the hands of customers.SCR-equipped passenger cars already meet the most stringent exhaust emissions standards in international markets such as the USA, Europe and Japan. Diesel engines with BlueTEC technology also reduce CO₂ emissions and provide the high torque and performance associated with the diesel engine in addition to keeping exhaust emissions at the lowest possible level.Nowadays the requirements for SCR emission concepts are increasing continuously. In fact the emission legislation is getting stricter with the LEVIII emission standards in 2015. Additionally the requirements and effort for on-board diagnosis are increasing year after year. In combination with ambitious CO₂ targets all these issues constitute the further challenges of BlueTEC SCR emission concepts for worldwide markets.The following challenges are the focus of efforts to further advance the BlueTEC drives: - Reduce development and calibration effort, - Standardize and reduce the costs of SCR components, - Improve performance by further reducing exhaust emissions (e.g., SULEV) and meeting the special requirements associated with the ever lower exhaust temperatures of vehicles designed to minimize CO₂ emissions, - Expand BlueTEC technology by integrating additional emissions components, and - Combine advanced BlueTEC emission concepts with CO₂ technology modules such as hybrid systems.The SCR-equipped diesel engines from Mercedes-Benz passenger cars represent ultra-clean drive technology, with low CO₂ emissions, that can be adapted for specific markets and vehicles in a modular fashion, ideally combined with other CO₂ technologies, and refined to meet future requirements.