Mercedes-Benz CLS running costs are fairly impressive considering the list price of the car. The upside is that the most frugal engine, the 250 CDI, returns 55mpg on average but the downside is the maintenance costs. If you do choose to have your CLS maintained at a pricey Merc dealership, however, you should expect excellent customer service. Insurance costs will be high too.

If you’re buying a new CLS from late 2014 onwards though you are able to save more, the new CLS 220 BlueTEC diesel managing to return up to 61mpg.

Being a luxury car, it isn’t exactly ‘green’ but Mercedes-Benz CLS emissions are low compared to other cars of the same size. This is partially thanks to its stop/start system and other Blue Efficiency technology. The four-cylinder turbodiesel-badged CLS 250 CDI with a 2.2-litre diesel engine emits 134g/km of CO2. The CLS 500 with its 4.6-litre V8 petrol engine emits 210g/km CO2.

It’s the new for 2014 CLS 220 BluTEC diesel that is the most efficient though, with CO2 emissions of 122g/km.

The CLS has an acceptable reliability record and there are no expected problems on the horizon for the new model. The out-going car had two recalls for minor issues with power braking and a possible loss of engine power. Mercedes-Benz reliability rates around average in consumer surveys.