Parkers overall rating: 4 out of 5 4.0

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

Petrol engines 6.9 - 8.6 mpp
Diesel engines 9.5 - 10.0 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.

Fuel economy

Petrol engines 32.5 - 40.4 mpg
Diesel engines 47.1 - 49.6 mpg
  • Impressive claimed fuel economy
  • Competitive BIK tax ratings – 30% for 200 d AMG Line
  • Pricier servicing and parts than non-premium manufacturers

The GLB delivers impressive claimed fuel economy figures across the range, with the most frugal being the 200 d version that delivers a claimed average of 49.6mpg on average. Even the petrol variants, 200 and AMG 35 4Matic, return between 38.7-40.4mpg and 32.5mpg respectively, under the more rigorous WLTP testing method.

If you’re considering the GLB as a company car, BIK (benefit-in-kind) tax rates vary depending on trim and engine size. The lowest rating belongs to the 200 d in AMG Line and AMG Line Premium specs (30%), while the GLB 200 petrol variant comes in at 31% but only in entry-level Sport trim. Both fuel economy and BIK ratings compare favourably with the BMW 2 Series Gran Tourer, a 220d Sport version returning between 50.4 and 54.3mpg and a 30% BIK tax rating.

In the real world, you can expect to get between 6.9 - 10.0 mpp (miles per pound), which is more than acceptable for an SUV of this size. Unsurprisingly, the diesel will go a lot further for your money than the petrol version.

Being a Mercedes-Benz, servicing and parts will be pricier than a non-premium manufacturer, however you should expect a higher standard of customer care at the dealership. Residual values for the GLB are yet to be confirmed.

Is the GLB reliable?

  • Too early for a definitive verdict
  • Shares parts and platform with big-selling A-Class
  • Unlimited-mile, three-year warranty on all new GLBs

It’s early days so we can’t give a definitive verdict on GLB reliability, yet. However, since it shares many parts (and a platform) with the big-selling Mercedes-Benz A-Class, logic dictates it should have plenty of time to iron out any issues.

In fact, the cars we drove on the launch felt more heavy duty than the A-Class, with a pleasing solidity to most buttons and controls – the cheap and tacky feeling stalks on the steering column being a notable exception. Like all new Mercedes-Benz models, the GLB comes with an unlimited-mile three-year warranty.

Ongoing running costs

Road tax (12 months) £150 - £475
Insurance group 27 - 41
How much is it to insure?