Updates shares move, adds background
** Shares in German truckmakers fall after President Donald Trump said the U.S. will impose 25% tariffs on heavy-duty trucks, starting October 1, 2025
** Traton 8TRA.DE and Daimler Truck DTGGe.DE are down between 2% and 3% after open
**On the other hand, stocks in peer Volvo VOLVb.ST are up 2%
** All of the Swedish firm's North American plants are located in the U.S. while Daimler Truck could see the largest impact given its significant footprint in Mexico
(Reporting by Ozan Ergenay, Paolo Laudani)
((ozan.ergenay@thomsonreuters.com))