INTERNAL COMBUSTION ENGINE AND METHOD FOR CONTROLLING THE SAME

Internal combustion engine comprising a plurality of cylinders with relative pistons, connected to a relative common drive shaft, said multitude of cylinders being divided into a first group and a second group of cylinders, in which consecutive ignition cycles alternate between the two groups of cylinders, the first group of cylinders being controlled to be always active, and the second group of cylinders being controlled to be active on request, the engine being characterised in that said first group of cylinders has a compression ratio different from a compression ratio of said second group of cylinders.