The Cayenne has been a runaway success for Porsche since its launch in 2002, and the addition of a petrol plug-in hybrid for the latest facelifted model will pique the interest for those business owners with the cash for this sort of car.

There was a hybrid in the Cayenne range before, but it wasn’t a plug-in, and it’s efficiency figures were no way near as impressive as this model, with a CO2 output of 193g/km compared with 79g/km for the S E-Hybrid. Not only have emissions been cut dramatically, but power from the lithium-ion battery has increased from 34kW to 70kW.

The Cayenne isn’t the only hybrid in the range, with the Panamera available with a version of the same technology and taking about 10% of total sales for that model. However, Porsche is expecting the Cayenne hybrids to be even more popular, accounting for around 15-20% of sales for the 4×4. It helps that there is pricing parity with the Diesel S model.

A spokesman from Porsche said Cayenne hybrid customers were likely to be company owners living around the London commuter belt and driving into the city’s congestion zone. Some owners will be trading in their Prius or other hybrids because they have been waiting for a model that fits their needs from both an image and tax perspective, while the overall cost of the car isn’t a massive issue for this sort of buyer.

As you would expect, the interior quality on the hybrid is to a very high standard, with plush, leather-clad surfaces dominating most touch points. There are some pretty striking fluorescent green brake callipers and instrument needles to highlight this Cayenne as a hybrid, along with some slightly less garish badging on the exterior.

The running costs are impressive, with a CO2 output of 79g/km putting it in an 11% BIK tax band. That means that even with a higher P11D price than a 3.0-litre diesel BMW X5, it still works out cheaper to run the Cayenne per mile at 105.8p, compared with the BMW’s 107.3p. That works out at £221 a month for a 40% tax payer compared with the X5’s £507.

Arguably, the Range Rover Sport hybrid is a truer rival. However, its astronomical P11D and running costs are easily blown out of the water by the new Cayenne. That cost per mile performance is also helped by the Cayenne’s incredible residual value, with it retaining 43.6%.

The actual hybrid system itself is quite subtle, and while it is possible to drive in pure EV mode with a potential range of 22 miles, the Cayenne’s lithium-ion battery will quietly provide emissions-free power at low speeds and crawling through traffic too.

Even in EV only mode, the 3.0-litre V6 will kick in past a preset point when drivers need to accelerate quickly to overtake. For a car of this size, the Cayenne is extremely nimble, with nicely weighted steering and it feels composed when turning into corners.

The Cayenne’s hybrid battery can be charged by the petrol engine on the move or through a three-pin plug socket at home or at the office. A 3.6kW charger comes as standard, and that offers a charge time of six hours. The time can be cut in half with an optional 7.2kW charger, but that would require a higher-capacity charging point to be installed.

Cayenne S E-Hybrid drivers also get access to a free Connected Car app as standard, which lets them view efficiency data, set a timer for charging the battery, or pre-heat or cool the cabin.