Mercedes Stops Testing EQS with 1.0-Liter Engine: Report

2025 Mercedes EQS

The tiny two-cylinder gasoline engine served as a range extender.

The EQS is built on a dedicated electric car platform, but Mercedes has been toying around with the idea of throwing in a gas engine. Not to drive the wheels but as a generator to juice up the battery on the fly. A new report claims testing of a prototype has been done with a tiny 1.0-liter turbocharged range extender. However, these trials have allegedly been suspended.

Autocar cites a Mercedes insider claiming the German luxury brand is no longer pursuing range-extending EVs. It’s deemed as a “transitional technology” that’s expensive to produce and brings only minimal benefits. The EQS allegedly had a two-cylinder version of the “M254” four-pot engine with an exhaust system mounted at the front of the car. Power came from a rear-mounted electric motor with 268 hp, drawing its energy from a lithium-ion battery pack installed in the floor.

The front-mounted ICE likely wouldn’t have hindered practicality since the EQS doesn’t have a frunk anyway. However, adding a combustion engine and a small fuel tank would’ve added weight to an already heavy car. An EQS 450+ tips the scales at 5,597 pounds while the AMG variant weighs 5,952 pounds.

Pricing would’ve been another issue. Logic tells us a range-extending EQS would’ve been more expensive given the extra hardware. The base model already costs six figures, starting at $104,400 and rising to $147,550, before options and the destination charge.

We’ve reached out to Mercedes for a comment, and we will update this story once we hear back. In the meantime, it’s worth noting the company inked a deal with Geely in late 2020 to work on hybrid powertrains. While range-extenders weren’t specified, we do know that China’s automotive juggernaut has this type of technology in its portfolio. The partnership stipulated that Geely-owned Volvo would also use those engines.

The company carrying the fabled three-pointed star is now channeling its efforts toward regular battery-powered EVs. The recently launched 2025 EQS is already a good cure for range anxiety since the enlarged battery (from 108.4 to 118 kWh) enables a maximum WLTP range of 511 miles.

EPA has not rated the revised model, but the old one did up to 352 miles on a single charge. WLTP is generally more optimistic than EPA, so don’t expect America’s EQS to have the same high rating as the equivalent European model.

The EQS SUVs:

Source: Autocar