New AMG variant of the G-Class spied sounding more powerful than the G55 - could be a G63 or G65 model.

The Mercedes-Benz G-Class is getting a little old but the automaker has committed to producing this model until 2015 and it seems they are not done yet with performance variants of it.

Spied testing here is a new and improved AMG variant of the G-Class, of which AMG already has one called the G55 that comes with a supercharged 5.5 liter V8 unit. The model was spied hot-weather testing and sporting larger air intakes at the front.

Our spy photographer reports that the car sounded 'very powerful'.

Could this be a G63 or G65?

We will have to wait and see.