If a vehicle is trying to overtake you, a radar senses as it enters the blind-spot area on either side of you, and alerts you by illuminating an icon in the side mirror. If you activate a turn signal, a warning tone sounds. The technology is called Active Blind Spot Assist.

If you’re approaching a slower-moving or stopped vehicle at a speed that suggests a collision is likely, a technology automatically provides the ideal level of braking. If you fail to react, the vehicle brakes itself. The Active Brake Assist is in play.

Yet another technology called Attention Assist monitors driving behaviour, and if it detects signs of drowsiness, it alerts you with visual and audible warnings. It’s time to have a cup of coffee.

These are among the dozens of in-car technologies we experienced while driving Mercedes-Benz GLS550 SUV from New York to Great Smoky Mountains National Park in Tennessee and back, a distance of over 1,500 miles (2,400 km).

Called the S-Class of SUVs, the GLS range is the successor to the GL-Class. In the US, Mercedes-Benz sells three models: GLS450 ($68,700), GLS550 ($93,850) and the AMG GLS63 ($124,100).

Of these, perhaps the best combination of power and efficiency is the GLS550. A perfect SUV for long-distance driving, it gets the 4.7-litre V8 biturbo petrol engine, which produces a peak output of 449-horsepower and maximum torque of 516 lb-ft. It goes from 0-60mph in just 5.2 seconds. The towing capacity is an impressive 7,500 lbs (factory-installed trailer hitch is optional, for $575).

The engine is mated to 9G-TRONIC automatic transmission; it changes gears almost imperceptibly. Relish fun driving? You can use shift paddles.

It’s a big engine, so despite fuel-saving features such as ECO Start/Stop—the engine automatically shuts off at stoplights or other idle situations—the rated fuel economy is 14 mpg (city) and 18 mpg (highway). You can achieve more by some smart driving manoeuvres—we got 21.5 mpg, by using cruise control as often as we could and driving within speed limits.

The 4MATIC all-wheel drive system makes it a vehicle for any season, any road. While driving from Tennessee to NY, we encountered heavy rainfall in Virginia, for over four hours, but the 4MATIC ensured the GLS550 remained in control, even at speeds of 70 mph.

All controls are driver-focused. Analogue gauges flank the coloured multi-information display in front of the driver. An eight-inch colour screen sits atop the dashboard. Standard amenities range from ventilated front seats, power front seats with memory, climate control, sunroof, massage function in seats, power-folding third-row, among others. It’s a seven-seater SUV, so the cabin is roomy, but third-row seats are cramped.

Leather upholstery is standard. For an extra $4,200, you can give your GLS550 the designo upgrade (designo is Mercedes-Benz’s selection of exquisite paint, leather and interior trim options). Options available are Nappa leather upholstery in Porcelain/Black or Espresso Brown, giving this luxury SUV a super-luxury treatment.

Another standard feature is the five-year Mercedes mbrace Connect Package, using which you get remote access to your GLS550 from your smartphone, including starting the engine from your phone to preset cabin temperature.

If you own a Mercedes, you need to feel special, too. The GLS550 gets side-mirror logo projectors, so when you remote-lock or unlock it, LED lamps beneath each side mirror project the “Star and Laurel” logo of Mercedes-Benz on the ground, welcoming you or seeing you off in style.

Mention must be made of Distance Pilot DISTRONIC. This radar-based cruise control makes highway driving extremely easy. How does it work? When the vehicle in front slows, DISTRONIC applies brakes; when the vehicle ahead speeds again, DISTRONIC steps on the gas until your car touches the preset cruise control speed. However, it’s not a standard feature, but part of the $1,375 Driver Assistance Package.

Then there is Crosswind Assist, a standard feature. It detects the effects of strong side winds on handling stability at highway speeds, and helps keep the GLS550 on course.

COMAND—short for Cockpit Management and Data system—is standard. The touchpad controller, made like a computer mouse, is placed between the front two seats and falls naturally to hand. It provides ready access to entertainment, navigation and car’s features. The sound system is by Harman Kardon. For an extra $5,400, you can enjoy Bang & Olufsen premium sound, but the system replaces spare tyre with TireFit sealant and portable compressor.

The GL-Class has metamorphosed into the GLS. Does it achieve the S-Class standards? Not yet. But as far as sheer luxury in an SUV is concerned, the GLS—with its rich appointments and raw power—leaves little to be desired.

The primary competitors of the GLS range in the US market are Audi Q7, Cadillac Escalade, Land Rover Range Rover, Lexus LX 570 and Infiniti QX80.

In India, Mercedes-Benz sells two GLS models: GLS350d diesel and GLS400 petrol, both about Rs 80 lakh, or $120,000.