In-depth Reviews

Mercedes SLC convertible - MPG, running costs & CO2

The diesel Mercedes SLC has impressively low running costs

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MPG, running costs & CO2 Rating

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Diesel is the way to go if you want your Mercedes SLC to be cheap to run. The car uses Mercedes’ long-standing 2.1-litre diesel engine – not the new one from the latest Mercedes E-Class saloon – but it boasts impressive fuel economy of 64.2mpg and CO2 emissions of just 114g/km all the same.

All SLC models come with fuel-saving technology, including stop-start, as well as a more economy-focused setting in the car’s Dynamic Select system. The Mercedes SLC is predicted to hold onto its value well, too. The SLK was particularly impressive in this area, with some of the lowest depreciation of any car on sale. The diesel model is a star performer in this area.

Mercedes SLC MPG & CO2

The economy hero of the Mercedes SLC range is the SLC 250d diesel. It returns a claimed average of 64.2mpg and CO2 emissions of 114g/km.

The petrol engines are less impressive. The entry-level SLC 200 emits 150g/km of CO2 and should return 43.5mpg. Oddly, the more powerful SLC 300 is more efficient than the SLC 200, emitting 138g/km of CO2 and returning an average of 47.1mpg.

As you would expect, the Mercedes-AMG SLC 43 is the most expensive to run, with CO2 emissions of 178g/km and 36.2mpg average fuel economy.

Every SLC costs £140 a year in road tax, unless the price (including options) exceeds £40,000, in which case there's a surcharge of £310 in years two to six, bringing the total to £450 during this period. 

Insurance group

Most versions of the SLC fall into insurance groups 41-45, while the higher-powered AMG version sits in group 47. This is similar to the Porsche 718 Boxster; the standard 2.0-litre 718 is in group 44, while the 2.5-litre S model is in group 46. 


As with all Mercedes cars, the SLC has a three-year/unlimited-mileage warranty.


Service intervals alternate between major and minor services, once a year or every 15,000, whichever comes about first. Mercedes offers a Service Care package that provides servicing cover for a fixed monthly fee of £35.

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