Parkers overall rating: 3.7 out of 5 3.7

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

Petrol engines 4.6 - 7.3 mpp
Diesel engines 6.6 - 9.7 mpp
Plug-in hybrid petrol engines 22.3 - 23.2 mpp
Plug-in hybrid diesel engines 28.5 - 30.0 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 21.6 - 34.4 mpg
Diesel engines 32.8 - 47.9 mpg
Plug-in hybrid petrol engines 104.6 - 108.7 mpg
Plug-in hybrid diesel engines 141.3 - 148.7 mpg
  • Premium badge limits depreciation
  • New engine line-up claims high fuel economy
  • Hefty fuel costs for AMG models

Mercedes-Benz has fitted a new range of four-cylinder engines to the GLC, and it makes modest claims about their fuel economy. The most efficient is the 220 d, which achieves 40.9mpg on the combined cycle and emits from 137g/km of CO2.

Though the 300 d claims poorer figures of 39.2mpg and 157g/km, we wouldn’t be surprised if its real-world economy was the same or greater than the 220 d’s, as the increase in power results in less need to rev the engine hard.

Both of these economy figures come from the tough WLTP testing cycle, so they should be more realistic than some rivals – though we found with the earlier 250 d engine that the claims were uncommonly accurate

The hugely powerful AMG GLC 63 and GLC 63 S models are ideal for those who simply don’t want to be burdened by money any more – they’ll spend it all fuelling these monsters. Cruising economy figures of more than 20mpg could be possibly with a particularly light right foot, but given the addictive power delivery in these cars some owners may achieve far less than this.

Green credentials

Opt for the cleanest GLC 220 d and you’ll enjoy CO2 emissions lower than any BMW X3 or Audi Q5 – at 137g/km, they’re impressive for a vehicle of this type. Do note that opting for bigger wheels or other choice optional extras will see this figure increase.

As with fuel economy, expect impressively high levels of CO2 to be produced by AMG models. The pre-facelift cars produced in excess of 270g/km, and we wouldn’t expect this to reduce post-facelift.


Since some slightly dodgy reliability records around the turn of the millennium, especially surrounding paint and rust issues, Mercedes has worked hard to ensure this has changed and so Mercedes-Benz GLC reliability promises to be excellent.

After all the engines and gearboxes are used throughout the rest of the current, and previous, range and have proved perfectly hardy.

The interior is borrowed from the Mercedes C-Class, so not only is it attractively designed, but it’s hardily built too. Our only concern is the propensity for the interior plastics, especially the piano black finish, to scratch and mark rather easily.

According to the firm’s marketing department at least, it’s designed to be used off-road too so should be capable of handling the rough stuff, so we don’t expect much of an issue with hard-used examples either.

It’s a little troubling, then, to see so many recalls on the against the GLC’s name. Scroll through the list and 2018 alone yielded eight, relating to everything from front seat belt tensioners not functioning to inadequate bonding of the windshield. Said issues were all fixed under warranty by Mercedes-Benz.

Ongoing running costs

Road tax (12 months) £125 - £475
See tax rates for all versions
Insurance group 27 - 49
How much is it to insure?