Most of us offroaders have debated endlessly on short wheelbases, solid axles, articulation, torque delivery, gearing, 4x4 tyres etc., and the effect each of these has on offroad performance. Full credit to the mechanical basics, but what role has technology played? The Classic / CJ340 is amongst the best Indian off-roaders, yet uses production design & tech that has been around since WWII.
Mercedes showcased some of their offroad technology at the "StarDrive in Mumbai" event last weekend. While the GL350 CDI is in no ways a hard-core offroader, do note that part of this tech is also available in the "G-Wagen" which is a highly-revered 4x4 (and others like the Landcruiser etc.).
Hari Singh (5 times National Rally Champion) was piloting the GL350 CDI that Team-BHP got a demo in. 510 NM of torque (starting @ 1,600 rpm), 275 width rubber on 19 inch wheels and the optional "
offroad pro package". The GL350 CDI has AWD and a low ratio transfer case which effectively gives the engine a total of 14 forward gear ratios to choose from. There's also a self-levelling suspension which maintains the same ground clearance, whatever the weight of passengers and / or cargo.
Simulation of driving over boulders:
At one point, two wheels (left front and rear right) were in the air, but the GL continued nevertheless. Thanks to:
- Max ground clearance of 307 mm! AIRMATIC air suspension that allows you to increase / decrease the ride height, depending on ground condition
- Traction control - Works in conjunction with AWD
- Individual wheel sensors - To gauge the grip available to each tyre and supply / disconnect power accordingly. Net net, they supply power to a multiple combination of wheels that have grip. Also, it will supply just the torque that the wheel can take (without slipping).
The "obstacles"
That's Hari Singh in the driver seat. Merc says their system is the equivalent of, and better than, three diff-locks. At this point, the RHS front wheel (and both rear) is given maximum torque, while the LHS is a mute spectator
The 4ETS gives max torque to the tyres with grip, and zero to the ones in the air:
An M Class was also part of the showcasing
Our superbly placed camera caught the action from the best view possible:
40 degree climb, and then descent:- Hill start assist : When activated, the SUV will not roll back on steep climbs (when taking off from a dead stop)
Wicked picture? Look closely
Why, its a GL staring skyward!
Hari Singh cool as a cucumber at this point. We came to a complete standstill, and then moved forward with the ease of doing so on a flat surface (Hill Start Assist at work)
Downhill speed regulation : Hari set a fixed speed of 4 kph (can choose between 4 - 16 kph in forward or reverse gears), and left it to the hardware / software. The SUV made light work of descending the steep decline with - you guessed it - zero drama. Not a wheel lost grip even momentarily
The seatbelts tighten up automatically to hold all 4 occupants firm, safe and in their intended place. If this was a slippery surface, the "
Offroad ABS mode" kicks in. The system gives more leeway, allowing tyres to "dig in". Merc claims that the offroad ABS system
reduces braking distances on loose surface
30 degree slope taken laterally:
Nope, I don't think anyone is going to be taking their GL for hard-core 4x4'ing anytime soon. The M-Class' bigger brother tips the scales at 2,450 kilos. Neither is it a body on frame. But it was fantastic to see some 4x4 tech in action. Now, how about an offroad test of the
G-Wagen?