2005 Kenworth W900. The engine sizes for the W900 range from 9 liters to 16 liters and it accommodates up to a 625-horsepower engine.- The W900 has front axles from 12000 to 22000 lb ratings and rear axles from 23000-lb single to 58000-lb tandems.- The "W" stands for "Worthington".1 W900 trucks are identifiable by their delicate external doorhandles mounted just beneath the side windows.- They ...