Mercedes-Benz will whip the covers off its S 500 Plug-In Hybrid next month at the Frankfurt Motor Show, however the German automaker has already released a slew of information about its technological flagship ahead of its official unveilling.
The most intriguing factoid is that the S 500 PHEV is claimed to consume just 3.0 l/100km and emit 69g/km of CO2 on the European combined cycle, which would make the large luxury sedan less thirsty than a Toyota Prius.
Granted, the plug-in version of the Prius (which isn't available in Australia) drinks even less fuel at 2.1 l/100km, but the Benz's result is all the more remarkable given its physical size and its 3.0 litre twin-turbocharged petrol V6 engine.
How does it achieve such sparkling fuel economy figures? By incorporating a mains-chargeable lithium-ion battery pack that can supply enough power for 30km of travel, reducing the S 500 PHEV's dependence on its petrol engine and allowing it to ace emissions and efficiency tests.
Regenerative braking helps prolong the S 500's electric-only range, and the driver can elect to reserve the car's electric power for later at the push of a button - handy when the first part of your commute is an easy highway cruise, followed by heavy stop-and-go traffic.
Intelligent engine management helps save fuel by using the car's sat-nav to keep tabs on the terrain. If it detects a long hill, then the petrol engine is shut down and a more aggressive regenerative charging mode is selected.
Bends and speed limits are also taken into account by the system, helping to reduce rolling resistance and, thus, fuel consumption.
The car can also operate as a regular hybrid, charging the battery while cruising yet augmenting the petrol engine's output while accelerating.
However, the plug-in charging method would yield the greatest fuel savings and is a trick reserved for the S 500 PHEV - the S 400 Hybrid and S 300 Bluetec Hybrid aren't able to charge their batteries from mains power.
Plant the right pedal in the S 500 Plug-In Hybrid, and you'll awaken the car's 245kW/480Nm 3.0 litre turbocharged V6. When working in concert with the electric motor, total system output is a healthy 325kW.
That's good enough for a 0-100km/h sprint time of 5.5 seconds and a top speed of 250km/h.
The Mercedes-Benz S 500 Plug-In Hybrid will be officially unveilled at the Frankfurt Motor Show in mid-September. We're still awaiting word from Mercedes-Benz Australia on whether the S 500 PHEV will find its way to our shores.