Mercedes-Benz G-Wagen gets bi-turbo V12

And the most remarkable thing is that it hasn't been discounted for Australia. The G65 AMG "G-Wagen'' - the world's most powerful production 4WD - could be the third model here after the G350 turbo-diesel V6 and G55 AMG V8 petrol.

Mercedes-Benz Australia says the same 450kW/1000Nm engine is in the S65 and SL65 and "at this stage we haven't confirmed the G65 AMG for our market''. Don't expect change from $550,000 if it makes it here - the fully-kitted G65 is two-and-a-half times the price of the G55 in Europe.

What you get is a lot of bang for a lot of bucks. The G65 is the world's most powerful cross-country production vehicle with its 6-litre bi-turbo V12 tuned for maximum horses and scant regard to fuel consumption.

Mercedes says the G65 will average 17 L/100km - but get it off the bitumen and that thirst could almost double. Mercedes revealed the G65 this week in its new line up of G-Class wagons for 2013.

Company spokesman Jerry Stamoulis says Australia will get the new model G350 BlueTEC and G63 AMG in April 2013. If you expect big styling changes, forget it - the extent of its external design upgrades consists of the addition of some LEDs under the headlights.

In Europe, the G-Class models includes the 155kW/540Nm 3-litre V6 turbo-diesel G350 BlueTEC and the 285kW/530Nm 5.5-litre V8 petrol G500, both as a long-wheelbase station wagon and the G500 as a short-wheelbase Cabriolet model.

The range lifts to the 400kW/760Nm 5.5-litre bi-turbo petrol V8 G63 AMG and then the G63. The upgrades for the 2013 G-Class are all inside the cabin. Mercedes says the upgrades "reemphasise its position as the leader among off-road vehicles''.

There is a redesigned instrument cluster and centre console with a colour screen between the two circular dials. Standard is Mercedes' Comand Online infotainment system with sat-nav and internet access.

The G-Class was conceived in 1979 as a vehicle to be used primarily in tough off-road terrain. Market demand has changed that direction. Over the past 33 years, Mercedes-Benz has refined the very practically oriented off-road specialist by giving it a high-class interior and road-going qualities on a par with those of its premium saloons.

"The G-Class today is considered the top model among luxury-class cross-country vehicles, and has provided the gene pool for the other very successful SUVs built under the Mercedes-Benz brand,'' the company says in a statement.