The new Cat 621H, 623H and 627H wheel tractor-scrapers feature a more powerful engine in the tractor, and a more powerful engine in the scraper of the 627H. The Cat C13 engine in the tractor produces 407 horsepower (18 percent more compared with G- Series models), and the C9.3 in the 627H scraper produces 290 horsepower (up 19 percent). In addition, a new torque converter is designed to deliver more power to the ground. Capacities are increased 2 cubic yards—to 24 cubic yards—for the single-engine/open-bowl 621H and twin-engine/open-bowl 627H. The elevating 623H is rated at 23 cubic yards and features a redesigned elevator that delivers more power and is easier to adjust. New software integrates the performance of the engine and eight-speed planetary transmission, and the new models also feature higher-capacity wet disc service brakes and new cabs that are 21 percent larger than G-Series models.