Hamburg - The rugged Mercedes-Benz G-Class is as boxy and utilitarian as the day it made its debut 30 years ago and that's exactly the way customers want it to stay.

The German maker's recent proposed dropping of this most Teutonic of all-terrain vehicles from the range sparked an outcry from dealers and fans with the result that the G-wagon is going as strong as ever.

Mercedes-Benz has never seen any reason to change the angular line of the G although behind those unfashionable Bauhaus-style flat panels, exposed door hinges and near upright screen the workhorse has come a long way.

When it first appeared in February 1979, the G-wagon (the prefix stands for the German word "Gelaendewagen") which translates as offroad vehicle - was anything but luxurious, with a frugal power plant and few interior creature comforts.

It was offered from the outset in a choice of five body styles all featuring a basic metal fascia and vinyl-covered seats. Power came from a choice of four petrol and diesel engines ranging from 72 to 150 horsepower.

By the 1990s, the G had moved away from its rustic roots to become a cult object revered from Moscow to California, a highly-desirable 4 by 4 with awesome prowess in the rough and stump-pulling performance to match.

Since then it has never looked back. Pop stars Eric Clapton and Tina Turner drive a G and actor-turned governor Arnold Schwarzenegger is a big fan.

Throughout its life, the G-Class has owed its ability off the beaten track to permanent four-wheel drive plus three manually selectable differential locks.

"Where there's a G-Class there's a way" is the advertising slogan for a vehicle which can descend slopes of nearly 80 per cent, has a maximum tilt angle of 54 degrees and ground clearance of 21 centimetres.

The latest versions come with ESP and brake assist systems as well as upmarket fitments such as polished alloy wheels along with burled walnut door caps and sumptuous leather seats inside.

Germany's respected Sueddeutsche Zeitung newspaper described the G-Class as majestic transport for the well-heeled: "Behind the wheel you expect to find a cross between Errol Flynn and a member of the German landed gentry. You ask yourself: 'Has the driver just come back from crossing the Savannah or touring his country estate in Westphalia'".

The origins of the G-Class go back to the early 1970s when the Shah of Iran was searching for a robust military vehicle to replace trucks in his army's fleet. The huge order for 20,000 was later cancelled by the country's new revolutionary rulers but Mercedes-Benz scored an early sales success with a version for armed forces in Argentina.

The Falklands War had strained relations with Britain, so Land Rovers were out of the question. Buenos Aires opted instead to buy made in Germany and hundreds of G-Class offroaders are still serving the Argentine military. Numerous military contracts followed and the G is used to transport soldiers and equipment from Afghanistan to Singapore.

Along with the Range Rover, the G-wagon spawned that class of offroad experts now known as sports utilitarian vehicles or SUVs for short, yet the concept was unknown three decades ago.

At that time, former Mercedes-Benz test driver Heinrich Wangler embarked on a promotional trip to the Middle East which lasted four months and covered 14,000 kilometres. Locals from Syria to Qatar marvelled at the strange test car from Germany which bounded across the desert, ploughing through sand dunes instead of driving around them.

"The car weighed next to nothing. We had no doors on it and a rudimentary windscreen which rattled the whole time," Wangler told the German offroad magazine 4 Wheel fun.

Of course, being accustomed to potent motive power, the Arab onlookers were puzzled at first by the puny engine. "They kept asking us if they could buy one with a complete engine instead of just the 'half of one' fitted," laughed Wangler, who has since retired and now chairs the G-Class owners club in Germany.

Unlike most SUVs, the G-wagon has bodywork mounted on a separate chassis like a small truck, with a sturdy ladder frame made of a stiff box section steel along with rigid axles and coil springs.

Proof of the robust recipe used to create the G was provided in 1983 when former Belgian Formula One driver Jack Ickx and Claude Brasseur won the punishing Paris-Dakar Rally in a modified lightweight aluminium 280 GE model. The offroader boasted some 230 hp, only 74 hp less than the standard model.

Over the years, the G-Class has been treated to some minor restyling yet its heritage is plain to see. The biggest changes have been under the bonnet, where larger engines cater for demands of a modern power-hungry clientele.

The ultimate high-performance G-Class variant is the V8-engined G 55 AMG which has been breathed on by the famous Mercedes-Benz tuning house. It boasts just over 500 horsepower and can bound from zero to 100 kilometres an hour (62 mph) in 5.6 seconds. Prices start at 108,000 (148,000 dollars) euros compared with around 70,000 euros (92,000 dollars) for a standard two-door G-wagon.

For three decades, the heavy duty vehicles have been made at the Magna-Steyr plant in the Austrian city of Graz where around 6,500 are largely hand built each year. Orders come mainly from the United States, Germany, Japan and Russia and so far some 200,000 of the G- Class have left the works. According to Mercedes-Benz, three-quarters of them are still in daily use.

An arduous factory test track for the trailblazing G-Class is located on top of a mountain just outside Graz. Hundreds of Gs have been put through their paces on these rocky trails with one notable exception - the crowd-friendly G500-based Popemobile cabriolet used by the Pontiff, Pope Benedict XVI.

Arguably one of the most famous cars on the planet, the stylish, pearlescent white-painted G was custom-built for the Holy Father in 2007 and can be regularly spotted in St. Peter's Square.