Verifying Power Claims of High-power Tractors Without a PTO at the Nebraska Tractor Test Lab

Nebraska law requires agricultural tractors of 29.8 kw (40 hp) or more to be tested and tractor power claims to be verified. In recent years, several tractor manufacturers have been producing models of large tractors either without a PTO or with a PTO not capable of transmitting the full engine power and, therefore, have chosen to advertise engine power. As the primary test the Nebraska Tractor Test Lab has used to verify manufacturers power claims has been the PTO power test, the manufacturers asked the University of Nebraska Board of Tractor Test Engineers to clarify how power claims for these tractors will be verified. Analyses of advertised engine power claims and drawbar power test results from 48 tracked and 43 4WD tractors were used to establish two linear relationships to verify the engine power claims for these types of tractors.