Mercedes says AI control of Rastatt's topcoat booths cut their energy use 20%

RASTATT, Germany, June 4, 2025 — Mercedes-Benz said using AI instead of conventional control systems in the Rastatt plant's topcoat booths cut their energy consumption by 20 percent and significantly shortened the process ramp-up. The plant began series production of the new CLA. Here's what happened, what it cost, and what went wrong.

Cost and outcome (as of June 4, 2025)

Outcome: "By monitoring relevant sub-processes using AI instead of conventional control systems, it was possible to reduce energy consumption by 20 percent and significantly shorten the ramp-up time of the process." (Mercedes-Benz, June 4, 2025)
Cost: Mercedes said it "has invested a mid triple-digit million euros amount in the production of the new model in Rastatt." It gave no figure for the AI work or the energy saved in euros. (Mercedes-Benz, June 4, 2025)
Claim: "Within just a few weeks, a new production line was configured and optimised in Hall 4.0" using digital simulation. (Mercedes-Benz, June 4, 2025)

Paint, and the line before it

Mercedes said Rastatt "pioneered the use of AI-controlled process engineering in the top coat booths." ASSEMBLY, June 4, 2025 reported the same 20 percent energy reduction in the paint shop's top-coat booths.

Before the CLA ramp-up, the plant remodelled an existing assembly hall "in record time," simulating the conversion virtually first. Mercedes said this delivered "considerable efficiency gains to be realised in terms of construction time and costs," though it did not quantify them. (Mercedes-Benz, June 4, 2025)

ASSEMBLY said the retooling was the first time the automaker's "digital first" approach was used, and that the line was configured "within several weeks." (ASSEMBLY, June 4, 2025)

Software without hardware modules

The CLA is the first car built in series with the Mercedes-Benz Operating System. Mercedes said its "chip-to-cloud architecture enables the vehicle software to be transferred via a central Mercedes-Benz Intelligent Cloud server instead of via various hardware modules," and called Rastatt "a blueprint for the global roll-out of MB.OS in all Mercedes-Benz vehicle plants." (Mercedes-Benz, June 4, 2025)

Rastatt's line is "fundamentally drive-flexible": hybrid, fully electric and conventional cars come off the same line. Electric drive units and axles come from Stuttgart-Untertürkheim, body parts from Kuppenheim and batteries from Kamenz. (Mercedes-Benz, June 4, 2025)

Energy at the plant

ASSEMBLY reported that production in Rastatt is carbon-neutral, supplied with 100 percent green electricity from solar panels and external supplies, with further savings from a new generation of body-shop robots, heat recovery in ventilation and intelligent lighting. (ASSEMBLY, June 4, 2025)

"The new CLA marks the start of another chapter in the more than 30-year success story of the Mercedes-Benz plant in Rastatt," said Jörg Burzer, board member for production, quality and supply chain. Site manager Marco Zwick said the team "has prepared intensively for this over the past few months." (Mercedes-Benz, June 4, 2025)

Winfried Kretschmann, Minister President of Baden-Württemberg, said the auto industry "is currently under enormous pressure due to changing market conditions, global uncertainties and crises," and called the CLA line "a commitment to Baden-Württemberg as an automotive location, to this plant and to the people who work here." (Mercedes-Benz, June 4, 2025)

Chairman Ola Källenius said the company is "investing to ensure that these can be 'made in Germany,'" adding that "a key prerequisite to make this possible is that framework conditions remain competitive." (Mercedes-Benz, June 4, 2025)

What went wrong

No baseline. Mercedes gives the 20 percent cut but not the booths' energy use before or after, or its value in euros. (Mercedes-Benz, June 4, 2025)
Single source for the number. ASSEMBLY repeats Mercedes' figure; it did not measure it. (ASSEMBLY, June 4, 2025)
Hall savings unquantified. "Considerable efficiency gains" in construction time and costs are not given as numbers. (Mercedes-Benz, June 4, 2025)
What we don't know yet: whether the 20 percent holds at full CLA volume and whether the AI booth control is rolling out to other plants.

Our follow-up question for Mercedes-Benz

What were the topcoat booths' energy use before and after AI control, and is it being rolled out to other paint shops?

Sources

Mercedes-Benz Group, “Digital, sustainable, efficient: Successful production of the new CLA at the Rastatt plant,” June 4, 2025. media.mercedes-benz.com
ASSEMBLY (Austin Weber), “Flexible Mercedes-Benz Plant Begins Assembling Next-Generation EV,” June 4, 2025. assemblymag.com

Disclosure: [not in copy] Editor placeholder