There no escaping that Mercedes-Benz GL-Class AMG running costs aren’t low.

With 550bhp being generated by the twin-turbo 5.5-litre V8 petrol engine driving all four wheels through a seven-speed automatic gearbox, Mercedes-Benz claims the official fuel consumption figure for the combined cycle is 23.0mpg.

In real terms this means you’re likely to experience a figure in the high teens much of the time.

Similarly, the Mercedes-Benz GL-Class AMG emissions figures are high at 288g/km of CO2.

This places it in the highest band, M, for VED road tax covering vehicles of 255g/km and above.

There’s little doubt over Mercedes-Benz GL-Class AMG reliability. This is a car that’s been engineered superbly and it feels it.

Everywhere you look and touch there’s a strong sense of solidity and robustness, all of it tastefully trimmed so that it looks expensive.

Trim feels like it will last the lifetime of the car; you’re not remotely concerned about treating switchgear with kid gloves for fear it’ll come off in your hands.

Two key areas which may affect reliability are how far off-road the GL63 AMG strays and the frequency of servicing those expensive mechanicals.

The GL63 AMG is a capable 4×4, even with those comparatively shallow tyre sidewalls and 21-inch wheels, so it’s susceptible to underbody damage if it hasn’t been driven with care.

Services are due as and when the car’s computer dictates but expect them to be more frequent and expensive than a more common diesel engine. AMG power units are finely-tuned performance engines and must be looked after.