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Mercedes-Benz SL-Class Convertible (2012-2020) running costs and reliability

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Running costs rating: 3 out of 53.0

Written by Parkers Published: 6 June 2019

Miles per pound (mpp)

Low figures relate to the least economical version; high to the most economical. Based on WLTP combined fuel economy for versions of this car made since September 2017 only, and typical current fuel or electricity costs.
Petrol engines 3.4 - 4.5 mpp
Diesel engines 3.7 - 3.8 mpp
What is miles per pound?

Fuel economy

Low figures relate to the least economical version; high to the most economical. Based on WLTP combined fuel economy for versions of this car made since September 2017 only.
Petrol engines 23.2 - 31 mpg
Diesel engines 28.8 - 29.7 mpg
View mpg & specs for any version

If you have the sort of money to indulge in an SL then you won’t be too concerned about the running costs. The most frugal version is the SL 350, which is claimed to return 41.5mpg on average. The SL will be fairly expensive to insure while parts and servicing costs will be high.

If you have a green conscience then the cleanest version of the SL is the 350. It emits 159g/km of CO2, which is not too shabby for a sporty convertible with a V6 engine.

The SL has had a chequered past in terms of reliability. There was a recall in 2004 following concerns about reduced braking efficiency and another in 2005 for an issue where the brake pedal required more effort than expected. Then in 2008 there was a further recall for a potential problem with the Active Body Control, which can affect driving stability.

More recent cars have proven to be more reliable.

Ongoing running costs

Road tax £305 - £735
Insurance group 48 - 50
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