ISO 789-13:2018

Overview

ISO 789-13:2018 is Part 13 of the ISO 789 series on agricultural tractor test procedures. It provides the authoritative vocabulary (terms and definitions) used across the other parts of ISO 789 and includes an informative specimen test report (Annex A) to standardize how tractor test results are recorded and communicated. This part ensures consistent terminology for tractor testing, measurement reporting and interpretation.

Key topics

• Standardized terminology for agricultural tractors and test measurements, including:
  • Definitions of agricultural tractor, wheelbase, track/tread, tractor mass, ballasted/unballasted mass
  • Engine and power-related terms: rated engine speed, maximum engine speed, engine power, power take-off (PTO) power, axle power, power at the drawbar
  • Hydraulic system terms: external hydraulic service, coupler pair, available differential pressure, maximum pressure, maximum hydraulic power, maximum usable hydraulic power
  • Performance and handling: maximum drawbar pull, dynamic radius index, turning radius/turning diameter/clearance diameter, slip, steering control effort
  • Fuel and reagent consumption: specific fuel consumption, specific energy, specific reagent consumption
  • Emissions-related component: diesel particulate filter (DPF)
  • Reference planes and centre of gravity coordinates for test set-up and measurements
• Specimen test report (Annex A) structure:
  • Manufacturer and assembly location, who submitted/selected the tractor, running‑in and test locations
  • Tractor identification and specification fields (make/model, transmission type, max ground speed)
  • Engine and components identification fields and further structured reporting sections for consistent results capture

Applications

ISO 789-13:2018 is used by:

• Test laboratories and certification bodies to ensure consistent interpretation of test methods and reporting across the ISO 789 series
• Tractor manufacturers and R&D teams to align internal test descriptions and specifications with international terminology
• Regulatory agencies and procurement teams that rely on standardized test reports for compliance, type approval and purchasing decisions
• Standards committees and technical writers for harmonizing cross-references within tractor test standards

Practical benefits include improved comparability of test data, clearer technical communication, and a ready-made template (specimen test report) that speeds up report preparation and reduces ambiguity.

Related standards

Part 13 supports other parts of the ISO 789 series and references terminology sources cited in the document, such as ISO 12934, ISO 10448, ISO 5700, ISO 6149, and OECD Code 2 - useful cross-references for specific test procedures and measurement definitions.

Keywords: ISO 789-13:2018, agricultural tractors, test procedures, tractor vocabulary, specimen test report, tractor testing, tractor terminology.