Ad closing in a few seconds...

Other Mercedes-Benz CLS models:

View all Mercedes-Benz CLS reviews
Parkers overall rating: 4.1 out of 5 4.1

Running costs

4 out of 5 4.0
  • Mercedes-Benz CLS tested on new economy standard
  • Mpg figures less impressive but slightly more realistic
  • Both diesel engines offer good economy, petrol less so

The new CLS is the first Mercedes-Benz to undergo the WLTP emissions test, which is tougher than the previous incarnation, though figures are currently backwards-calculated to be broadly comparable to the previous test.

As such, the economy figures look slightly less impressive than other models from the German manufacturer, but should be a little closer to what you’ll actually achieve.

Currently the best mode for low running costs, unsurprisingly, is the lowest-powered diesel, the CLS 350 d 4Matic, which boasts 48.7mpg when driven carefully.

The more potent CLS 400 d 4Matic uses the same basic engine and as such offers a broadly similar 47.9mpg despite packing a more sizeable punch.

Worst off is the CLS d 450 4Matic with a claimed 36.2mpg – still a reasonable figure considering the size and performance of this sporty coupe.

Four-cylinder engines will be introduced to the CLS shortly after launch and should improve the coupe’s running costs. We’ve driven the 2.0-litre petrol but its economy figures haven’t been released yet.

Estimated fuel cost per year

Fuel type Pence per litre Estimated cost per year *
Unleaded 128p £1,492 - £1,877 *
Diesel 131p £1,215 - £1,267 *

* The estimated fuel cost figure is based on an annual mileage of 10,000 miles and is a guide to how much this model will cost in fuel each year. It's calculated using the model's average MPG (calculated from both town centre and motorway driving) and the average fuel price from around the country. Actual fuel costs will vary based on driving style and road conditions.

Ongoing running costs

Servicing period Variable intervals, fixed-cost packages available
Warranty Three-year, unlimited mileage
Road tax (12 months) £465
Insurance group 47 - 50
How much is it to insure?

Vehicle excise duty (VED) varies according to the CO2 emissions and the fuel type of the vehicle. For cars registered before 01 March 2001 it is based on engine size. For cars registered on or after 01 March 2001 the VED or road tax is based on the car's CO2 emissions.

Green credentials

3.8 out of 5 3.8

Mercedes CLS: will it be eco-friendly?

Currently the Mercedes-Benz CLS is only available with six-cylinder powerplants, so those looking for a greener version of the coupe should wait for its entry-level four-pots, which arrive after launch.

For now though the CLS 350 d and 400 d 4Matics offer the same 156g/km of CO2, while the CLS 450 4Matic claims a comparatively less impressive 184g/km.

Still, Mercedes-Benz says this model features a similar amount of power as the previous V8 CLS 500, while putting out 23% less CO2, so that’s quite clever.

Highest and lowest CO2 emissions

Engine CO2 emissions Road tax (12 months)
d Diesel 149 g/km (Min) £465
3.0 Petrol,
p Petrol
203 g/km (Max) £465


4 out of 5 4.0
  • Lots of shared tech with E-Class
  • New engines are a bit of an unknown
  • Should be a fairly solid car though 

Given that the Mercedes-Benz is based on the E-Class’s architecture we’d suggest its components should be reasonably well tried and tested.

However, all of the engines are new and in Mercedes’ own words, very sophisticated, so time will tell how those fare.

As a manufacturer Mercedes-Benz has historically been a bit patchy in terms of reliability but its latest generation of cars certainly seem to be moving the game on.

Car checklist problem points

Body No problems reported.
Engine / gearbox No problems reported.
Other No problems reported.

Next steps