General Guidelines for Tractor Weight Based on PTO Kilowatt

Travel Speeds

The total tractor weight needed to efficiently deliver power through wheels to ground for field draft applications depends on travel speed. The table shows recommended weight per PTO kilowatt for three draft speed ranges.

  Light Medium Heavy
       
Ground Speed 8.7 km/h (5.4 mph) and faster 7.2 - 8.7 km/h (4.5 - 5.4 mph) 7.2 km/h (4.5 mph) and slower
       
Kg/PTO-kW 41 45 48
       
Lb/PTO-HP 120 130 140

 

Wheel slip should normally be in the range of 8-12% for optimum power delivery efficiency at these field speeds. Wheel slip may briefly rise above this range when tractor encounters a higher draft area in the field, but it should not stay there continuously. Add more

weight to drive wheels if slip is excessive. If there is less than minimum percent slip, ballast should be removed, unless needed for stability.

NOTE: It is recommended to use the radar to continually monitor wheel slip. Checking wheel slip manually is possible but will only show slip in one area of the field.

IMPORTANT: To extend drive train life, tractor should never be operated with continuous full-power loads below 6.4 km/h (4.0 mph). Ground speed may briefly drop below that level in hard pull situations, but it must recover to higher levels during normal operations. This applies to tractors with all types of transmissions. For tractors equipped with AutoPowr transmission operating in automatic mode, the engine will not labor in extremely high draft situations, but minimum ground speed guideline must still be followed.

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