Mercedes is launching a new low-emission range, called BlueEfficiency, at next week's Geneva motor show, although plans to bring them to the UK haven't yet been finalised.
The plan is to roll out 20 BlueEfficiency models over the next year, with the C180 Kompressor, C200 CDI and C350 CGI first in line.
Weight has been saved on all the cars by using a thinner windscreen, less sound proofing and lighter alloy wheels and low-rolling resistance tyres. Aerodynamic work has also reduced drag significantly.
The C200 CDI BlueEfficiency records the greatest gains. Its 2.2-litre diesel engine has 134bhp and 199lb ft of pulling power, yet manages 55.4mpg and emits just 135g/km of carbon dioxide, compared to the standard model's 46.3mpg and 149g/km.
The C180 Kompressor BlueEfficiency gets a smaller capacity 1.6-litre engine, but keeps the same power and torque figures. It manages 43.5mpg - 7.3mpg more than the standard model - and emits 156g/km of CO2 rather than 177.
The C350 CGI BlueEfficiency is powered by a new 3.5-litre petrol V6 with 289bhp and 269 lb/ft of pulling power, which is 20bhp and 11lb ft more than the standard car's V6 unit. It manages 33.6mpg and emits 220 g/km of CO2, 4.5mpg and 12g/km less than the current unit.
A Mercedes UK spokeman said: 'We're still discussing what models to bring to the UK and when they will be available. But once we know which cars fit our market, they will go on sale here.'
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