Four Caterpillar wheel tractor-scrapers—the 621G, 627G, 631G and 637G—feature new operator stations with improved ergonomics, a redesigned scraper bowl with 10 percent more capacity, and the latest electronic monitoring system. Both the 627G and 637G tandem-powered machines have new electronically controlled scraper engines that incorporate dual power capabilities. The three implement levers (bowl, apron, ejector) are incorporated into one electro-hydraulic joystick controller. All models have new, adjustable seats that swivel and lock in four positions. Estimated list prices: $500,000 to $1,000,000.