Porsche’s classic 911 gets an overhaul in the summer, featuring new, more efficient engines with reduced emissions.

Brand new flat-six units – either 3.6 or 3.9-litres in capacity – feature direct fuel injection and Porsche’s new optional double clutch transmission, called PDK.

They will be available in four new 911s – two coupes and two cabriolets.

Fuel economy is up to 29.4mpg and emissions on the 3.6-litre engine are reduced by up to 15% to 225g/km, putting it in VED band F and reducing company car tax costs.