Mercedes releases 6x6 G63 AMG specs and pics [w/video]Fri, 15 Mar 2013 Mercedes-Benz has finally dropped full details on its insane G63 AMG 6x6. The machine puts 544 horsepower to all six wheels thanks to a twin-turbocharged 5.5-liter V8. A seven-speed gearbox shuttles power to the ground via three sets of portal axles, which helps give this machine a full 15.75 inches of ground clearance. By comparison, the standard G63 AMG sits with just 8.27 inches of ground clearance. The extra lift allows this 6x6 to ford nearly 40 inches of water and run massive 37-inch tires. All told, there are five differential locks on this thing, all controlled by a special "locking logic" that provides the best traction possible for any given situation.
The controls offer up three stages of locking, which we can only assume range from JKLOL to OMGWTF. Right now, AMG says this monstrosity is only a show vehicle, but we imagine it wouldn't take much to convince the team to whip up one of your very own. Check out our full gallery and the press release below for all the nitty gritty. While you're down there, you can also check out the video on the machine one more time.
6x6 Drive technology: Ideal partnership: Off-road high-performance technology and AMG power
Innovative 6x6 drive with central through-drive axle
Huge ground clearance and fording depth thanks to portal axles
Total of five 100% differential locks
Massive pulling power from AMG 5.5-litre V8 biturbo engine
Short shift times with AMG SPEEDSHIFT PLUS 7G-TRONIC
A look at the key data of the G 63 AMG 6x6 makes it clear that this model's off-road world begins at a point where anything less than a vehicle with caterpillar tracks would have to capitulate. Six driven wheels, an off-road low-range ratio in the transfer case, portal axles and five differential locks which can be engaged on the move are features which one seeks in vain in conventional off-road vehicles. Together, they ensure that the G 63 AMG 6x6 has driving dynamics which are more than a match for the toughest terrain. As a result, the show vehicle is able to storm up the highest sand dunes with ease while sand tracks hold no fears thanks to its unshakable directional stability. Rocky terrain is negotiated with all the agility of a mountain goat; fording a river becomes almost child's play thanks to the impressive fording capability. And anyone exploring the on-road performance is certain to be impressed by the catapult-like acceleration of this 3.85-tonne pickup.
Despite its unique drive technology, the show vehicle does not actually represent a new development in terms of technology. After 34 years of G-Class production, there is such a large array of "G" parts to draw on that the G 63 AMG 6x6 uses almost exclusively series-production components under the skin. A case in point is the drive train: the AMG V8 engine, the AMG SPEEDSHIFT PLUS 7G-TRONIC automatic transmission and the front drive system have been taken over from the G 63 AMG while the transfer case with low-range ratio has been matched with a rear twin drive train from a 6x6 version which has already proven its reliability in service with users such as the Australian army.
Technical highlight: the portal axles
Newly developed for a wide variety of applications, the portal axles which have been added to the Mercedes-Benz off-road portfolio are the real technical highlight of the show vehicle. Unlike conventional rigid axles, where the wheels are centred on the axis of the shaft, the wheels of the portal axle are significantly lower thanks to the portal gears on the axle heads. As a result, the ground clearance of the G 63 AMG 6x6 is increased to 460 millimetres (series-production G-Class: 210 millimetres) and the fording depth – or maybe it would be more accurate to say diving depth – is increased to 1000 millimetres (series-production: 600 millimetres).
This design has further important benefits which do away with the need for elaborate adaptation measures. As the position of the axles relative to the chassis remains unchanged, so too do the suspension anchorage points, the steering connection and the position of the propshafts. Furthermore, the portal gear reduction ratio compensates for the huge rolling circumference of the 37-inch tyres so that the gear ratios, speedometer drive and ABS sensors also remain unchanged. An additional benefit of the reduction ratio applied by the portal gears is that the drive torque is only applied to the wheels themselves with the result that the mechanical loads on the drive train – especially the drive shafts – are reduced.
Through-drive: the centre differential
A technically sophisticated solution provides the 6x6 drive system with the necessary through-drive through the differential of the first rear axle to the rear one. The arrangement which has been developed is extremely compact and requires little more space than a conventional differential housing. An extra shaft with an integrated lock situated on the side above the differential takes the drive torque to the rear axle. A chain provides the necessary power take-off for the differential of the first rear axle.
Precisely coordinated logic governs operation of five differential locks
With a total of five mechanical 100-percent differential locks available, drivers would certainly lose track of the settings now and again if they could be engaged separately. This is why the engineers have developed a special locking logic which ensures the best possible traction is available in every situation. The whole system is controlled electrically with the usual three differential lock switches in the centre console which are to be found in all G models. Preselected and engaged locks are indicated by yellow and red lights respectively.
Stage 1: the two inter-axle differential locks in the transfer case and in thethrough-drive through the centre differential are active
Stage 2: the interwheel differential locks in the tworear axle differentials are additionally activated
Stage 3: with the front axle differential locked, allfive differential locks are now active
All lock stages can be selected regardless of whether the low-range ratio in the transfer case is selected.
It is clear that, with a wheelbase of some 4.20 metres, the G 63 AMG 6x6 is not predestined for virtuoso cornering. Nevertheless, in order to ensure impressive agility with corresponding dynamism about the vertical axis of the vehicle, the engineers have varied the torque distribution. The drive torque is therefore split 30 to 40 to 30 percent between the front axle and the two rear axles.
V8 biturbo from power specialists Mercedes AMG
Much of the credit for the superior performance of the G 63 AMG 6x6 is due to the AMG V8 engine and the AMG SPEEDSHIFT PLUS 7G-TRONIC automatic transmission. The AMG 5.5-litre V8 biturbo engine develops a peak output of 400 kW (544 hp) and 760 newton metres of torque. Known in-house by the designation M 157, the engine impresses with its technological highlights. The greater thermodynamic efficiency which results from the combination of twin turbochargers, direct petrol injection and spray-guided combustion allows better fuel economy and leads to lower exhaust emissions. Fast and precise piezo-electric injectors spray the fuel into the combustion chambers, ensuring a particularly fine distribution throughout the air in the combustion chamber. An electric low-pressure pump delivers the fuel from the tank to a high-pressure pump in the engine compartment at a pressure of six bar. The fuel pressure in the high-pressure rail is controlled between 100 and 200 bar on a fully variable and demand-related basis, ensuring an agile response in any driving situation. Further highlights of the innovative and unique eight-cylinder powerplant from AMG in Affalterbach include an all-aluminium crankcase, four valves per cylinder with camshaft adjustment, air/water intercooling and alternator management.
Any doubts about the show vehicle's ability to speak directly to the emotions are quickly dispelled by a look at the AMG sports exhaust system: twin tailpipes ahead of the rear wheels on both sides put out the hallmark AMG eight-cylinder sound.
Faster shifting with the AMG SPEEDSHIFT PLUS 7G-TRONIC
Featuring three drive modes and an automatic double-declutching function for downshifting, the AMG SPEEDSHIFT PLUS 7G-TRONIC automatic transmission delivers the drive to the transfer case with low-range ratio by means of a propshaft. "Controlled Efficiency" (C) mode calls up engine and drive control strategies designed to deliver a driving style which is as economical as possible. In the Sport (S) and Manual (M) driving modes, the engine-transmission combination displays considerably greater agility. Here, a brief and exactly defined retardation of ignition and injection during upshifting at full load provides for shorter shift times. Furthermore, in "M" mode, the G 63 AMG 6x6 maintains the gear selected by the driver to the extent that this is permitted by the engine rev limits – a particularly useful feature when negotiating challenging climbs.
The efficiency of the AMG SPEEDSHIFT PLUS 7G-TRONIC automatic transmission system is further enhanced with a new fuel economy converter with centrifugal pendulum, friction-reducing bearings and transmission oil thermal management.
It makes sense to provide an ample fuel supply for vehicles which are designed to be used in remote areas. This is why the standard production tank with a capacity of 96 litres has been complemented by a 63-litre auxiliary tank. The total tank capacity therefore amounts to 159 litres.
G 63 AMG 6x6 near-series show vehicle: Taking the desert by storm
Stuttgart. Superior 6x6 all-wheel drive technology, AMG V8 biturbo power and looks that leave no room for any doubt: the Mercedes-Benz G 63 AMG 6x6 near-series show vehicle is an off-roader which represents the last word in forward-thrusting power far from the beaten track. 400 kW (544 hp), a 6x6 drive, low-range ratio, five differential locks, portal axles, tyre pressure control system and a special chassis allow this pickup to make good progress in environments where the concept of individual mobility normally bites the dust as soon as the road ends. But anyone who imagines that this is a Dakar-Rally-style vehicle is on the wrong track. Thanks to the wealth of interior enhancements from the AMG stable, the occupants can enjoy the highest possible degree of comfort, even when negotiating the worst that the combined forces of topography and meteorology can throw at them. The exclusive touches even extend to the load area which is finished in solid bamboo.
The Mercedes-Benz G 63 AMG 6x6 near-series show vehicle brings together the best of three worlds. The latest, revised G-Class series-production models lend the superior off-roader the effortless superiority and refinement of a vehicle which has dominated the off-road scene for 34 years. They are also the source of the up-to-date interior concept with the contemporary dashboard featuring impressive new instruments and a large, central colour display. Unreserved robustness as well as practicality and a can-do attitude to off-road driving are the traits inherited from the military and the commercial G-Class models. Finally, the renowned Mercedes-AMG luxury and performance division contributes the superior engine technology and the interior which is as luxurious as it is comfortable.
6x6 technology: to the ends of the earth – and beyond
A look at the key data of the G 63 AMG 6x6 makes it clear that this model's off-road world begins at a point where anything less than a vehicle with caterpillar tracks would have to capitulate. Six driven wheels, an off-road low-range ratio in the transfer case, portal axles, five differential locks which can be engaged on the move and a tyre-pressure control system which allows the pressure in the huge 37-inch tyres to be adjusted in record time while the vehicle is running – all these are features which one seeks in vain in conventional cross-country vehicles. Together, they ensure that the G 63 AMG 6x6 has driving dynamics which are more than a match for the toughest terrain. As a result, the show vehicle is able to storm up the highest sand dunes with ease while sand tracks hold no fears thanks to its unshakable directional stability. Rocky terrain is negotiated with all the agility of a mountain goat; fording a river becomes almost child's play thanks to the impressive fording capability of one metre. And anyone exploring the on-road performance is certain to be impressed by the catapult-like acceleration of this 3.85-tonne pickup.
Despite its unique drive technology, the show vehicle does not actually represent a new development in terms of technology. After 34 years of G-Class production, there is such a large array of "G" parts to draw on that the G 63 AMG 6x6 uses almost exclusively series-production components under the skin. A case in point is the drive train: the AMG V8 biturbo engine with 400 kW (544 hp) and 760 newton metres of torque, the AMG SPEEDSHIFT PLUS 7G-TRONIC automatic transmission paired with the front drive system from the G 63 AMG and a rear twin drive train from the 6x6 version which has already proven its reliability in service with users such as the Australian army. Plus the ingenious portal axles, which also have military origins, here making their debut in a civilian vehicle.
Independent and neutral: the chassis
The chassis is largely based on the current production configuration, the only difference being that the helical springs and dampers have been adjusted to take account of the changed characteristics of the three-axle model. For the springs, too, the engineers were able to draw on the comprehensive array of "G" parts, which includes no less than 15 different spring rates. While the front axle takes over the reinforced springs from an armoured special-protection variant, the first rear axle has been given a significantly harder spring rate and the second rear axle a softer one. This set-up, together with the rally-proven, adjustable gas-pressure shock absorbers, results in a perfect symbiosis of sporty dynamism and composed comfort, on or off the road.
Macho outside – S-Class inside
Visually, the G 63 AMG 6x6 pickup leaves no room for any doubt as to its true calling. The large tyres on the three axles, the huge ground clearance, the height of almost 2.30 metres and the width of some 2.10 metres as well as the clean-cut lines of the pickup immediately inspire respect. Like the G 63 AMG and G 65 AMG models before it, the super off-roader with its 5.87-metre-long body has the characteristic AMG brand face with the "twin blade" radiator grille. Other visual highlights include the use of elegant carbon fibre for the integrated LED light strips above the windscreen as well as for the large flared wheel arches while the rear load area section has a distinctive stainless-steel roll-over bar. The load area, which is lined with particularly tough and durable bamboo, can be accessed by means of a tailboard.
Sporty luxury, the hallmark of AMG, is the defining characteristic of the interior. The G 63 AMG 6x6 welcomes its occupants aboard with an exclusive ambience of classic red or light brown designo leather with contrasting topstitching and attractive diamond-pattern quilting. The four electrically adjustable individual seats are heated and ventilated. The rear compartment is equipped with a special centre console while the roof liner and pillars are finished in an Alcantara® covering.The rear panel is trimmed in leather.
Graz is the centre of the "G" world
The two G 63 AMG 6x6 vehicles which have been built to date were developed with Mercedes-Benz at the helm. The Graz-based Mercedes-Benz G-Class development department is the centre of competence for all "G" projects and is responsible for development and series support of the legendary cross-country vehicle. Furthermore, Graz in Austria has been the production site for all civilian and commercial G-Class vehicles since 1979. The response to the near-series show vehicle will determine if and when the Mercedes-Benz G 63 AMG 6x6 enters small-series production.
By Zach Bowman
See also: Next Mercedes-Benz GLK to get AMG variant? Not likely..., X1, 3 Series power BMW back into global luxury autos sales lead, 2014 Mercedes-Benz SLS AMG Black Series [w/video].