Possible suppliers include US based companies Detroit Diesel Inc., John Deere & Co., Caterpillar Inc., Cummins Inc. and International Truck & Engine Corp. To be a successful truck company, Toyota will definitely require a range of diesel engines in its pickups, and according to Toyota's executive vice president of engineering and manufacturing for North America, Gary Convis, the company realizes that it’s important to develop a diesel.
Toyota is not completely lacking an internal diesel option. Instead of outsourcing engines, it may simply rely on Hino, its commercial trucking company. The Tundra is probably Toyota’s most important vehicle in its future line-up. The company estimates sales of the new vehicle to top 250,000 units per year, which is double its current rate. Toyota’s rival Nissan is currently in negotiations with International for a diesel V8 for its Titan pickup and Cummins already supplies engines for the popular Dodge Ram pickup.
Via AutoWeek