Mercedes will begin manufacturing its E-Class mileage-meister next year. When the company's first diesel-electric powered car was previewed at the Geneva auto show in March 2010, production was promised for 2011. Now executives admit the hybrid version of the E-Class won't be showroom-ready until sometime in 2012.
Not only has the launch date slipped, but so has fuel economy. According to Joachim Lindau, senior manager for E-Class (and CLS) testing, the target for the production E300 BlueTec Hybrid is 53 mpg in the standard European fuel consumption test. While impressive, this is 4 mpg less than the efficiency promised a year ago at Geneva. What hasn't changed is the hybrid's horsepower. Lindau says the combined maximum output of the diesel-electric powertrain remains 221 hp.News of the production delay for the hybrid came at a recent event in Germany to preview a slew of efficiency-enhancing powertrain changes for the existing E-Class range. Notably, the gasoline-burning V-6 and V-8 used since launch in 2009 are replaced by the more powerful engines introduced late last year in the closely related CLS. This means an all-new 302-hp direct-inject 3.5-liter V6, plus a downsized 402-hp direct-injection and twin-turbo 4.7-liter V-8. The four-cylinder powertrains, not sold in the U.S. but popular almost everywhere else, were also significantly updated. And it's here that likely reasons for the delay in the hybrid program are to be found.


The E300 BlueTec Hybrid is to be based on the E250 CDI with its 201-hp 2.1-liter four-cylinder turbodiesel. But before hybridization, a bunch of enabling technologies need to be in place. These preparations are still some way from completion. The E250 CDI gained two of those technologies in the recent round of upgrades; it now has an auto start-stop system, and Mercedes' hybrid-friendly seven-speed auto has replaced the five-speeder. But the E250 CDI still lacks some vital technologies. The biggest of these is electric power steering, deemed essential for any hybrid.