Adding a new hybrid model each year from 2009 onward will lay the groundwork for Mercedes-Benz raising hybrid sales to 20% of its corporate total by 2015, according to the latest reports. The goal reflects the current state of legal requirements and customer demand, while positioning the brand to continue beyond the eventual end of the combustion engine.

The doomsday for the conventional engine is still at least 20-30 years out in Mercedes' eyes, however, reports Auto Motor & Sport. It won't be a sudden transition, either - the German carmaker sees it as a gradual series of steps, from today's offerings to hybrids to diesel-hybrids, such as the GLK BlueTEC hybrid (pictured), to arrangements where the combustion engine plays a decreasing role and the electric drivetrain comes to the forefront. Eventually, power, performance and range of the electric side of the system will be good enough to dispense with the combustion side entirely.

Already Mercedes-Benz is planning to be the first major carmaker to market with a lithium-ion battery-powered hybrid in the form of the S400 Hybrid - though it may be beaten by any number of smaller companies. That will mark one of the evolutionary steps in the improvement of the electric portion of the hybrid drivetrain. Following the S400 Hybrid will be the ML450 Hybrid in 2009, which will face strong competition from BMW's X6 ActiveHybrid among others.