Both cars will be based on the large E-Class sedan, debuting in E 300 diesel-electric hybrid form for Europe and, for the US market, the E 400 petrol-electric hybrid.
In E 300 form, the hybrid system will feature a 150kW diesel engine paired with a 20kW electric motor inside the transmission housing and drawing energy from a 0.8kWh lithium-ion battery.
The E300 hybrid's all-electric driving range is less than two kilometres, but the motor's real goal is to help reduce CO2 emissions and fuel consumption.
According to Britain's Autocar magazine, the E 300 hybrid will release just 109g/km of CO2 - 40g/km less than BMW's ActiveHybrid 5, and fuel consumption will be as low as 4.9 l/100km - compared to 8.3 l/100km for the current E 250 CDI BlueEfficiency.
The saving - almost half - is thanks also to the use of stop/start, brake energy recuperation, low rolling-resistance tyres and a special coasting mode.
The E 400 hybrid bound for the US market pairs a big 3.5 litre V6 petrol engine with the same electric motor, returning fuel consumption figures of 8.7 l/100km, compared to 9.8 l/100km for the petrol-powered E 350 offered in Australia.