If you're shopping for a new tractor and want to know how brands compare in power and performance, check out the results of tractor tests compiled by an independent, economic think tank.

The Organization for Economic Cooperation and Development (OECD)produces comprehensive reports on new tractor models manufactured almost anywhere in the world. The organization has been developing international standards for testing tractors since 1959. These have enabled 30 official examination centers in 28 countries to conduct harmonized tests. So far, the centers have evaluated the performance of 1,970 tractors and have measured noise levels and assessed the rollover protection of 10,000 tractors.

OECD member countries that have staged these standardized tractor tests include Britain, France, Germany, Japan, South Korea and the United States. In America, the tests are conducted by the Association of Equipment Manufacturers (AEM) in Chicago and the Nebraska Tractor Test Laboratory at the University of Nebraska.

Test data are divided into eight sections, called codes: two for performance, five for protective structures and one for noise. The performance tests look at main power takeoff; hydraulic power and lifting force; drawbar power (with and without ballast); turning area and turning circle; position of center of gravity; braking; external noise level; traction power; and fuel consumption of the tractor without ballast. Tests are conducted on tractors that have not been modified and are operating as specified by the manufacturer.

Emmanuel Hugo of Cemagref, the French company that compiles and checks the test reports, says that farmers can learn a great deal about a tractor's performance from the test reports. “The lower the specific fuel consumption, the better the efficiency of the tractor,” he explains. “So this may be an element in a farmer's choice for tractors having the same maximum PTO power.

“Useful also is the torque rise of the engine,” he adds. “The higher the value of the torque rise, the easier the possibility for the tractor to accept an overload without the need for the driver to change the gear ratio.”

A copy of Abstracts of Agricultural Tractor Tests: 2002 Edition (results from 2001) costs $22, plus postage and packaging. To order, call 800/456-6323. To view the report for free, visit www1.oecd.org/agr/code/tractors/index.htm.