YOU can now have two cars in one: a high-performance vehicle in the shape of an SUV. Here's one take on the theme.

Value

At $164,530 plus on-road costs it adds up to about $185,000 by the time you're in the traffic. That's a power of money but it's a powerful SUV. It's as quick as a Porsche 911 but can carry five people and their luggage in comfort and safety - it's loaded with the latest tech.

Under the bonnet is a hulking twin-turbo 4.0-litre V8 that puts out an epic 375kW of power and 700Nm of torque. Downsides? A three-year warranty at a time when five years or more are becoming the norm. Servicing intervals are generous at 12 months/20,000km but the costs are steep: $4570 over three years, including a $2660 visit at the two year/40,000km mark alone.

Comfort

Being the sporty version the front seats have large side bolsters to keep you in place. The grip from the massive 21-inch wheels are tyres means the side bolsters aren't just for show.

They're a bit of a nuisance when getting in and out but you're thankful for them once on a winding road. Back seat space and the cargo area are generously-sized. Imagine a Ford Territory with supercar levels of power and you get the idea.

Safety

Nine airbags - including a driver's knee airbag and rib-protecting airbags in the outer positions of the front and rear seats - gives above average occupant protection. A 360-degree camera and front and rear parking sensors take the hassle out of squeezing into tight spots.

Autonomous emergency braking will avoid a crash at suburban speeds by slamming on the brakes if the driver is distracted, and mitigate crashes at freeway speeds.

Driving

The sound of the exhaust will have the neighbours thinking a V8 Supercar driver has moved in next door, although thankfully there is a quiet mode for more discreet arrivals and departures. The acceleration is mind-boggling for such a big SUV.

Mercedes claims a 0-100km/h time of 3.8 seconds. It's splitting hairs but the best we could get was 3.9 seconds. Such discrepancies matter to rev heads but the uninitiated will be blown away, such is the force of the acceleration. Big wheels and sports suspension means it's a bit bumpy on back roads and the tyres make a lot of noise in tight turns at parking speeds. This is the trade-off for taut handling in corners.

The cost to replace all four tyres is as much as an old used car - more than $2000 a set - so buyers probably won't want to wear them out too quickly.

Alternatives

BMW X5M, from $189,000

BMW's nearest German rival for now. It's just as quick and costs just as much but has a more fiddly infotainment system.

Ranger Rover Sport SVR, from $238,000

The UK's answer to the super-fast German SUVs. Powered by supercharged 5.0-litre V8, it howls.

Porsche Cayenne Turbo, from $239,000

The pinnacle of European performance SUVs. Acceleration is maybe a fraction quicker than its peers but you'll pay a premium to trim a tenth or two from your dash to the speed limit.

Verdict

The Mercedes GLC63S AMG brings muscle car performance - and sound - to the civilised world of SUVs.

At a glance: Mercedes GLC 63S AMG

Price: $164,530 plus on-road costs

Engine: 4.0-litre twin-turbo V8, 375kW/700Nm

Safety: 5 stars, 9 airbags, autonomous emergency braking, rear cross-traffic alert, blind zone warning, 360-degree camera

Transmission: 9-speed auto, all-wheel-drive

Thirst: 10.9L/100km (claimed)