Smaller and lighter-weight cars, that boast a powerful yet small displacement engine, have an easier time of it. Many such engines comprise a turbocharger that makes a difference only when you floor the gas pedal. Moderate and savvy driving will not make much use of the turbocharger, which will result in more fuel-efficent car performance. How about large engine displacement vehicles? It goes without saying that their appetite will be ravenous, regardless of how fuel-efficient your driving. A reasonable solution to this, more so than in vehicles with small displacement engines, would be a classic engine combined with an electric motor.

Porsche did just that with the Panamera, the SUV Cayenne and the 918 Spyder super sports car. The latter, which deserves to be praised on all fronts, has already sold out all 918 units.

That leaves us with the Panamera and Cayenne. They both feature a combination of a classic engine and an electric motor, producing a system output of 416 horsepower and 590 Nm of torque. The Panamera weighs 2095 and the Cayenne 2350 kilograms. The average fuel consumption for the Panamera, as estimated by the manufacturer, is 3.1 liters per 100 kilometers, and 3.4 liters for the Cayenne. Science fiction? At first glance, yes.

Having won first place at the Porsche E-Challenge for journalists who, in the outskirts of Stuttgart, set out to drive as fuel-efficiently as possible, I may now be singing a different tune. Especially since, after a 50-plus kilometer drive on regular roads (high-ways included), with more traffic than usual, the on-board computer indicated that the average fuel consumption was 2.9l per 100 km. This means that the actual consumption did not just match, but bested, the official estimate. The challenge thus proved that official consumption estimates can be met without concerted effort, providing your battery is fully charged (the Panamera can cover 18-36 km on electricty alone). Even in a two-ton vehicle with over 400 horsepower engine.