Mercedes-Benz S 500 plug-in hybrid in showrooms in July image

Clients seeking to buy what should be the most fuel-efficient luxury sedan in the world have a little while to wait, as the model draws near the actual sales start.

The Mercedes-Benz S 500 Plug-in Hybrid was officially revealed to the public during the 2013 Frankfurt Motor Show and is now only the second plug-in hybrid in the luxury segment, besides the Porsche Panamera S E-Hybrid.

The S 500 also boasts a very impressive fuel consumption figure – which is also very hard to believe – the automaker claims it will only need 3 liters of fuel for each 100 km (78.4 mpg). That’s surely subject to change in real world conditions – and also depends on the driving style.

Under the hood of the S 500 plug-in, a powerful combustion engine of 333 hp and 480 Nm (354 lb ft) of torque is combined with an electric motor generating another 109 hp and 340 Nm (251 lb ft) of torque. That’s enough to get the big sedan to 100 km/h in just 5.5 seconds (which would for sure make the consumption go over the fence) and reach an electronically limited top speed of the usual 250 km/h flavor.