Parkers overall rating: 3.7 out of 5 3.7

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

Petrol engines 2.6 mpp
Diesel engines 3.8 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 17.2 mpg
Diesel engines 25.7 mpg

Running costs: 1.9 out of 5.0

  • An expensive car to run
  • Expect big fuel bills
  • Strong residual values

You only get a choice of two engines with the G-Class, and neither are particularly small or economical. The sensible choice is the G400d, a 2.9-litre six-cylinder diesel that's only able to muster around 26mpg in official tests. Thankfully, you'll get a little more than that in the real world with a gentle right foot, with high 20s achievable without too much sweat.

The other option is the brawny 4.0-litre V8 G63 which is officially capable of around 17mpg. Drive carefully and you might just about hit 20mpg, though. Naturally servicing will be costly, although G-Classes do hold their value very well. Even so, with the range starting at around £100,000, you'll still lose plenty of cash if you buy new.

Green credentials: 1.5 out of 5.0

At the moment the G-Class is anything but green. Even the diesel emits nearly 300g/km of CO2 placing it firmly in the top 37% BIK company car tax bracket. The G63 emits over 370g/km, a staggeringly high figure these days.

No hybrid version is offered, although an all-electric version has been shown as a prototype and is said to be entering production.

Reliability 4.6 out of 5.0

  • Should be a reliable prospect
  • A very tough, strong car
  • No problems anticipated

The Mercedes-Benz G-Class has a good reputation for reliability, as befits one of the toughest 4x4s on the market. The current model is based on an entirely new architecture, around a strong ladder-frame chassis. Even so, it uses plenty of existing Mercedes tech so you shouldn't get too many issues.

Ongoing running costs

Road tax (12 months) £490
Insurance group 50
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