The EQS will compete with the Taycan and its upcoming Audi E-Tron GT sibling in the flourishing electric premium saloon segment. Test mules feature a low, swooping roofline, with a slim headlight design among the more obvious visible features.
The EQS is described as being roughly the size of the current CLS. Mercedes previously hinted at the styling of its first electric saloon with the EQS Vision concept at last year's Frankfurt motor show.
The latest addition to Mercedes' EQ electric vehicle line-up will join the EQC mid-sized SUV and EQA compact SUV in showrooms in 2021. According to officials, the EQS name implies a level of luxury, comfort and features consummate to the company’s traditional S-Class.
It will head what the engineering boss of the EQ sub-brand, Michael Kelz, suggests will be a 10-strong electric model range by the middle of the 2020s.
Whereas the EQC is based on existing underpinnings from the GLC, the range-topping EQS will be the first EQ model to benefit from Mercedes' dedicated Modular Electric Architecture (MEA).
The EQS is expected to be powered by two electric motors – one on the front axle and the other at the rear – providing permanent four-wheel drive. In the EQC, this set-up delivers more than 400bhp and some 516lb ft.
Mercedes has confirmed the EQS will be produced at its main Sindelfingen factory on the outskirts of Stuttgart. It's the third plant in Germany earmarked to produce an EQ model, with the EQC set to be built in Bremen and the EQA at Mercedes' compact car plant in Rastatt.