The Mercedes E300 BlueTEC Hybrid has arrived in UK showrooms, with prices starting from £39,645 for the saloon and £41,435 for the Estate.
The new hybrid - which is the most efficient E-Class ever - undercuts the similarly sized BMW 3.0 ActiveHybrid 5 by around £6,500, but is over £11,000 more expensive than the E250 CDI on which it's based.
The E300 Hybrid uses a 201hp 2.1-litre four-cylinder common-rail diesel engine and a 27bhp electric motor powered by a lithium-ion battery pack. An EV mode allows it to travel on electric power alone for a kilometre, with the diesel engine kicking in at speeds of more than 22mph.
Thanks to fuel-saving technology such as regenerative braking and a sailing mode, the E300 is capable of returning 65.7mpg and 109g/km of CO2 on 16-inch alloy wheels, which are a no cost option instead of the standard 17-inch alloys.
It can also accelerate from 0-62mph in 7.5 seconds (the Estate manages it in 7.8 seconds) and go on to a top speed of 144mph.
Deliveries of the Mercedes E300 BlueTEC are due to begin in November.