Parkers overall rating: 4.8 out of 5 4.8

Miles per pound (mpp) Miles per pound (mpp)

Petrol engines 4.0 - 7.7 mpp
Diesel engines 7.8 - 8.9 mpp
Plug-in hybrid petrol engines 22.3 - 27.4 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.
Based on "Weighted" mpg; figures depend on the proportion of miles driven in pure electric mode and may vary widely

Fuel economy

Petrol engines 18.6 - 36.2 mpg
Diesel engines 38.7 - 44.1 mpg
Plug-in hybrid petrol engines 104.6 - 128.4 mpg
  • No S-Class is particularly inexpensive to run
  • Diesels make for the best all-round buys
  • Ensure your pockets are very deep for a V12

Mercedes S 350 d badge

Diesels will be the way to go for manageable everyday running costs, with fuel economy ranging between 38.7mpg and 44.1mpg for the S 350 d and S 400 d models. The S 450 L and S 500 L both claim up to 36.2mpg, while the S 560 e L offers up to 128.4mpg, but this is only achievable if you make full use of the plug-in drivetrain and charge it as often as psosible. 

Unsurprisingly, the AMG model and you can expect pretty woeful fuel economy. The S 63 L manages 23.2-24.4mpg, while the V12-powered S 65 L musters just 18.6mpg on the combined cycle.

All petrol S-Classes suffer in terms of depreciation, too, potentially retaining only a third of their value after three years and 36,000 miles-worth of driving. Diesels perform better, but still only hover around the 40% mark.

If you’re of the opinion you’ll be able to run an S-Class inexpensively, think again before you make a serious mistake. This is a big, heavy and powerful car, meaning consumables such as tyres and breaks, let along services, will be wallet warping.

If CO2 emissions are your priority, the S 560 e L is what you'll want, with a figure of as little as 57g/km. Moving up the range and the S 350 d emits just 158g/km (AMG Line), with Grand Edition models emitting 2g/km more. Even the S 400 d emits the same despite its higher power output. 

Petrol models aren't much worse, with both the S 450 L and S 500 L producing 169-171g/km. 

Go for an AMG models and things are slightly different. The S 63 L emits 231g/km which isn't too bad considering its 612hp output, but the V12-powered S 65 L emits a whopping 325g/km of CO2. 

2018 Mercedes S-Class side profile

Is it reliable?

  • A dozen recalls so far for this S-Class
  • Seven of those relate to stop/start system
  • No issues so far with raft of safety kit

Think Mercedes-Benz and you invariably think of its high-quality range of cars, with premium prices to match, yet this generation of S-Class Saloon has so far been subjected to 12 recalls by the vehicle inspectorate, the DVSA. That’s both eye-opening and disappointing.

By now these issues should have been remedied by a Mercedes-Benz dealer, but it’s worth confirming this if you’re considering buying a used S-Class. Somewhat alarmingly, seven of the recalls relate to problems with the stop/start system, while a further two concern the automatic transmission. Two more recalls were airbag-related, while there was another one linked to the seatbelts.

Searching for some good news, none of the recalls relate to the raft of electronics for the cabin or the safety-related equipment. We've heard of several electrical problems blighting S-Class owners too along with some rattling trims after not many miles at all. 

Ongoing running costs

Road tax (12 months) £0 - £580
See tax rates for all versions
Insurance group 44 - 50
How much is it to insure?