The new Porsche Cayenne might have a new face and even more performance, but the Cayenne S Hybrid is the perhaps the most significant step forward the new model has taken.

The second-generation Porsche Cayenne is the follow-up to the biggest-selling car the company has ever made; and as we found out recently, it’s improved in almost every way.

But the game is moving on, and it’s no longer enough to offer only petrol and diesel versions of your car. So, the Porsche Cayenne is the first car in its class to be offered in petrol, diesel and hybrid versions.

And don’t think it features hybrid technology sufficient only to power the car’s stop start system – this is a full-fat hybrid that works in a similar way to the eco car poster boy, the Toyota Prius.

The Porsche Cayenne S Hybrid combines a supercharged 3-litre V6 engine developing 333bhp with a 47bhp electric motor to produce 380bhp and 428lb/ft of pulling power.

Superb performance

That places it close to the 400bhp Cayenne S in the performance stakes, with a 6.5 second 0-62mph time and a 150mph top speed. But it’s closer to the diesel for fuel consumption – it’ll cover 34.4mpg, less than the diesel’s 38.2 – but emissions are lower.

Rated at 193g/km, they’re the lowest of any Porsche currently on sale.

Porsche has been keen to push its new technology, but not at the expense of the driving dynamics the company is famous for. The heavy batteries are housed beneath the floor, to avoid upsetting the Cayenne’s poise and balance, and the whole package works seamlessly on the move.

At speeds of up to almost 40mph, the Hybrid can run on electricity alone, and under moderate acceleration, the engine powers the wheels in isolation. Accelerate harder, and the engine power is boosted by the battery, providing the car’s impressive acceleration.

Under braking, power is generated to recharge the batteries.

Porsche Cayenne gallery:

Engine-free driving at 97mph

Cleverly, the Hybrid can disengage the engine at cruising speeds up to 97mph without the drag and engine braking the engine could otherwise cause. As with the rest of the hybrid technology, all this happens in the background, with no input necessary from the driver.

A series of instruments in the main binnacle and on a touch screen in the dash provide information on the state of charge, how the hybrid system is functioning and a rev counter which enters an ‘idle’ state when the engine cuts out and the electric drive train kicks in.

One display on the screen shows statistical information on the journey and the percentage of the journey travelled in zero emission mode.

The Cayenne S Hybrid marks the first time hybrid technology has been applied to one of its road cars. With a system which works as smoothly as this, without an impact on the sportiness of Porsches cars, it won’t be the last.

Key facts:

Model tested: Porsche Cayenne S Hybrid
On the road price: £57,609
Price range: £41,404 – £81,589
Date tested: June 2010
Road tester: Stuart Milne

Manufacturer footage: