The Navistar T444E is a Diesel V8 engine manufactured by Navistar International Corporation. In its use in Ford Motor Company trucks, vans and school buses, it is the first of the PowerStroke family of diesel engines. The T444E was manufactured from 1994 to 2004, replacing the 7.3 L IDI V8 designed by International Harvester. As a result of federal emission standards, the T444E was discontinued midway through the 2003 model year, replaced by the all-new 6.0 L VT365. In total, nearly 2 million 7.3 L PowerStroke V8s were manufactured for Ford at their Indianapolis, Indiana plant before switching to the 6.0 L.