The Cayenne S E-Hybrid is the first plug-in hybrid in its segment, though BMW has hinted that it will offer something similar in the new X5 in the near future. It is also Porsche’s third plug-in hybrid, after the 918 supercar and the Panamera S E-Hybrid, with which it shares its drivetrain.

Designed to offer performance and economy in one package, the Cayenne S E-Hybrid combines a 3.0-litre supercharged petrol engine producing 330bhp, with a 94bhp electric motor powered by a lithium-ion traction battery.

Combined, these can offer 412bhp and allow the Cayenne to reach 62mph in 5.9 seconds, but the electric motor can also be used to drive the car between 12 and 24 miles at up to 77mph. Based on  the NEDC plug-in hybrid combined cycle, fuel economy is 83mpg with CO2 emissions of 79g/km.

Significantly, though, Porsche has priced the Cayenne S E-Hybrid at £61,474, which is identical to the 381bhp Cayenne S Diesel, which returns 35.3mpg and emits 209g/km CO2. The manufacturer said this is aimed at giving consumers the choice between two equivalent drivetrains based on the driver’s needs. 

Unlike the Panamera S E-Hybrid, the Cayenne's CO2 emissions mean it is not eligible for the £5,000 Plug-in Car Grant, exemption from the London Congestion Charge and doesn't fall into the heavily discounted 5% Benefit in Kind tax band for ultra-low emission vehicles.