Parkers overall rating: 4.2 out of 5 4.2

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

Petrol engines 4.5 - 4.7 mpp
Diesel engines 6.4 - 6.5 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.

Fuel economy

Petrol engines 21.1 - 22.1 mpg
Diesel engines 31.7 - 32.1 mpg

How much does the Mercedes-Benz GLS cost to run?

  • Diesel the best performer for fuel consumption
  • Unlikely to be cheap to maintain
  • Things like tyres will be expensive

The GLS 400 d is capable of 29.7-30.9mpg, according to Mercedes-Benz. As the engine is fairly effortless, this shouldn’t be too difficult to achieve if you take it easy.

These are the only figure available for now for cars arriving in the UK ahead of the rest of the range.

How eco-friendly is the Mercedes-Benz GLS?

Go for the GLS 400 d and CO2 emissions are rated at 208g/km. There are no figures as yet for upcoming GLS 450 and AMG GLS 63 variants, but you can certainly expect the hot AMG version won't be that kind to the environment. 

However, the GLS 450 comes with what Mercedes calls EQ Boost. It's a 48v mild-hybrid system that not only boosts performance, but it also makes the car quicker and more efficient to start up and switch off when the engine is warm. 

Is it reliable?

The GLS is covered by Merc’s standard three-year/60,000-mile warranty if anything goes wrong. The previous model was the subject of just one recall regarding the power steering, and no others. This latest GLS is all-new however, with new components shared with the latest GLE. There are a lot of systems to go wrong, but it all feels solidly put together and would have been tested thoroughly to put up with the rigours of life as a luxury SUV.

Ongoing running costs

Road tax (12 months) £475
Insurance group 47 - 50
How much is it to insure?