Mercedes-Benz describes the F700 as “a futuristic interpretation of the classic saloon” and predicts much of the technology it previews will begin appearing on production models within the next decade as emission regulations become ever more stringent and buyer expectations are boosted by advances in other fields, most significantly those in consumer electronics.

While officials are quick to play down the relevance of the new four-door’s styling, Mercedes-Benz sources Drive spoke to suggest various themes explored within its body are likely to be developed further before being committed to production, including its bold front-end treatment which is said to preface the look of its future line-up.

More than its radically styled exterior, however, it is the one-off saloon’s compact variable compression twin-turbocharged 1.8-litre four-cylinder DiesOtto petrol engine that Mercedes-Benz promises will have the biggest bearing on its future model range.

The new DiesOtto engine is claimed to offer the power, smoothness and low emissions of a typical petrol engine in combination with the torque, flexibility and frugal properties of a diesel. The new engine is capable of switching between two distinctively different ignition processes depending on the driving conditions.