Daimler has thrown a firing shot at Tesla’s ability to deliver 500-mile range electric trucks by 2019.

According to Daimler trucks head Martin Daum, in pointed remarks made at a press pool event in Stuttgart, Germany, he cited existing battery technology and Tesla’s curious 2019 production timeline as reasoning for his skepticism.

“If Tesla really delivers on this promise, we’ll obviously buy two trucks — one to take apart and one to test because if that happens, something has passed us by,” Daum said. “But for now, the same laws of physics apply,” he added.

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In the same press event, Daum revealed plans to mass produce shorter-range electric trucks than Tesla’s own, to participate in a series of trials before mass production starts in 2021. Its initial fleet of 10, 124-mile range, Mercedes Benz electric Actros (e-Actro) will showcase Redeka and Hermes, a German supermarket and parcel delivery service, in a trial to test its viability on city distribution routes.

Two versions of the e-Astro will debut, weighing 18 and 26 tons, respectively, with a recharge time between three to 11 hours depending on the version.

This trial is expected to last two years, bolstered by Daimler’s investment of $616-million (€50-million euros) over the next two years towards the development of its electric truck and battery technology.

Last year, the iconic German automaker and subsidiary Mitsubishi Fuso Truck and Bus also debuted the E-Fuso Vision One, a Class 8 truck, at the Tokyo Motor Show, sporting a 210-mile (350-km) range with an 11,000-pound load rating to serve short-haul deliveries, initially. Its latest electric model debuted shortly before Tesla’s own Class 8 the same month.