Total U.S. tractor sales increased 9.8% in September compared to last year, but have declined by 1.3% through September 2005 compared to the same time last year. Large tractors (100 hp and up) and 4-wheel-drive tractors, however, continue to show increases this year. In fact, 4-wheel-drive sales soared 47.1% in September compared to a year ago and are up 13% over last year's sales pace.