While its S 300 BlueTEC Hybrid stablemate pairs a 2.1 litre diesel engine with an electric motor to achieve an impressive fuel figure of 4.5 l/100km, the S 500 PHEV takes efficiency for a large luxury car to an all-new level.
First revealed in August last year, Benz has exceeded its own initial estimate of 3.0 l/100km for the S 500 PHEV, with an official fuel figure of just 2.8 l/100km - breaking the magical 100 miles-per-gallon barrier at 100.9 and rivalling single-cylinder scooters for efficiency.
The S 500’s electric-only range has also been slightly underestimated, with the PHEV able to travel up to 33km on battery power alone, rather than the predicted 30km range.
Behind the impressive economy numbers is a 3.0 litre twin-turbocharged V6 petrol engine producing 245kW and 476Nm, matched with an 80kW electric motor for a combined output of 325kW/650Nm.
While this figure falls short of the ‘regular’ S 500’s 4.7 litre petrol V8 engine with power and torque of 335kW and 700Nm respectively, the V8 sees average fuel usage of 9.2 l/100km.
The battery pack is an 8.7kW/h lithium-ion unit mounted within the boot, with an expected recharging time of around 2.5 hours.
The S 500 PHEV isn’t slow with a zero to 100km time of 5.2 seconds, but it is 0.4 seconds slower than the eight-cylinder S 500; thanks in part to the PHEV’s 200kg weight-penalty, which sees kerb weight rise to 2140kg.
Mercedes-Benz recently expanded its S-Class range in Australia, introducing the S 300 BlueTEC Hybrid and three new long-wheelbase models.
Pricing for the regular S 500 in Australia currently starts at $285,000, rising to $310,000 for the long-wheelbase version.
No word yet from Mercedes-Benz on whether we’ll see the S 500 Plug-In Hybrid in Australia.