• Use the performance and pay
• G 63 rewards gentle driving
• G-Class will outlast most cars, too

Mercedes-Benz G-Class running costs are, unsurprisingly, quite high. Even though it’s powered by a 3.0-litre diesel engine, the vehicle’s impressive 2,570kg kerb weight goes some way to knocking the claimed average economy figure down to just 25.2mpg. In day-to-day use it’s likely you’ll see the G-Class return around 20mpg.

Choose the petrol powered Mercedes-AMG G 63 and Its 5.5-litre twin-turbocharged V8 is likely to average between 10-15mpg in daily use, despite optimistic claims of 20.5mpg; Eco mode, with stop/start and restrained use of the power does go some way to meeting those claims though.

Road tax costs are high too, due to emissions of 295g/km of CO2 at best. Unfortunately there are plenty of big bills waiting for you elsewhere. Servicing and repair bills won’t be cheap and replacement tyres and braking components will prove alarmingly expensive.

If you’re looking at buying an older example, it’s worth taking into account the fact that as the car ages it could become increasingly difficult to maintain and repair. Even a simple fault could require substantial disassembly of the Mercedes-AMG G 63, racking up high labour charges. On the plus side, major mechanical issues should be few and far between.

Despite a range of modern emissions control systems, the Mercedes-Benz G-Class isn’t particularly environmentally friendly. One thing the G-Class does have going for it, however, is that it’s likely to last a long time. That will help minimise its total impact on the environment a little.

The 3.0-litre diesel V6 emits 295g/km of CO2, resulting in a hefty showroom tax bill and high yearly road tax costs. It’s not particularly economical either, with a claimed average fuel consumption of 25.2mpg.

Turbocharged V8 is understandably far from green

The Mercedes-AMG G 63’s emissions are rated at a substantial 322g/km of CO2. That means you’ll be paying a considerable amount for road tax each year, as well as being hit with a large initial showroom tax bill.

Fuel economy won’t impress either, with the G 63 being claimed to average 20.5mpg. Its real-world economy will most likely be considerably less than that, though it’s better than you’d expect in urban driving if you use Eco mode.

You might think that’s par for the course for a powerful off-roader but alternatives like the Porsche Cayenne Turbo are much cleaner. The Porsche is also faster, more efficient, considerably more competent on the road and far less costly.

• Incredible body and mechanical quality
• Technology is likely to be less robust
• Sophisticated engines

As you’d expect, Mercedes-Benz G-Class reliability is excellent. The car features a lot of well-proven parts and technology and the G-Class is highly regarded for its durability.

Given that most G-Classes will spend their time in city centres and on motorways, as opposed to pounding desert tracks, they should last well.

The modern electronic systems and more complicated powertrains may prove costly and difficult to maintain in the future, compared to older iterations of the G-Class, however.

One thing that’s worth bearing in mind is that the Mercedes-AMG G 63 is a complicated off-roader that’s very tightly packaged. As it gets older it may become increasingly expensive and difficult to maintain, particularly compared to older versions of the G-Class.