IoH/Ag CMV Weight Table
The following weight table is for Implements of Husbandry (IoH) and Ag Commercial Motor Vehicles (Ag CMV) based on s. 348.15 (3) (g) Wis. Stats. A pdf version of this information is available here. The distance between the axles is measured in feet between the foremost and rearmost axles of a group. The number of axles is counted by vehicle or combination of vehicle
Determining the weight of an IoH or Ag CMV
To determine the maximum GVW (Gross Vehicle Weight) of your IoH or Ag CMV when maximum axle weight apply requires several measurements.
Total distance from the center front axle to the center of the rearmost axle of the vehicle or vehicle combination. In the example the total distance is 39 feet 6 inches and you can round up; to 40 feet. Measuring is defined in s. 348.15(5m) Wis. Stats.Use this distance with Column A of the IoH/Ag CMV Maximum Weight Table- Next step is to measure between the individual axles. Axles need to be at least 42 inches apart to count as separate axles. This helps you determine the number of axles that will apply on the IoH/Ag CMV Maximum Weight table. The example IoH vehicle combination has 5 axles.
- Now that the maximum gross vehicle weight has been determine, it is time to review the individual axle weights. Each axle must carry at least 8 percent of the gross vehicle weight. to qualify as an individual axle per s. 348.15(8) Wis. Stats. Maximum axle weight is 23,000 pounds. If you have an axle that exceeds 23,000 pounds, you’ll need to obtain a No Fee Permit to operate on highways were the maximum axle weight apply. To review roads that require maximum axle weights see Local Options.
Back to the IoH/Ag CMV Maximum Weight Table with the number of axles. For this example, Column E (5 axles) will be used. Follow Column A across and where it intersects with Column E that is the maximum gross vehicle weight for this combination.The maximum gross vehicle weight for this farm tractor and tanker is 84,000 pounds. To exceed this weight, you will need to obtain a No Fee Permit or haul a lighter load.In the example, the manure tanker has unladen weights. For some vehicles you’ll need to consider loaded weight of the vehicle. One factor to consider is that towed implements may add weight to the rear of the towing power unit. - Measuring axle gauge.Bridges are designed for the standard width of commercial motor vehicles of 8 feet 6 inches. Agricultural vehicles, primarily IoH, are wider than the standard commercial motor vehicles. In reviewing permit applications with routes including bridges, axle gauge is a needed measurement. It is used by bridge engineers to assess where the vehicle will travel on the bridge and the impact of the vehicle on the bridge supports.Axle gauge is measured from the center of the axle or axle group to center of the axle or axle group.
To measure the axle gauge on this farm tractor, measure from the center of the left group of wheels to the center of the right group of wheels. In this case, the center of the group is the center of the middle wheel. 
Effective March 3, 2016, farm machinery dealers in Wisconsin must now provide unladen gross vehicle weight and axle weight in writing. This is not required for private sales or auction sales.
Taking the time to measure and weigh your implements of husbandry and agricultural commercial motor vehicles is an important first step to determine which vehicles may need a No Fee Permit to operate legally on Wisconsin highways.
General Weight Information
General Weight Limits
Size, Weight and Load provisions may be found in Chapter 348 of the Wisconsin Statutes.
For vehicles not meeting the IoH or Ag CMV definitions, weight limits are found in subchapter III. Class A highway limits are set per s. 348.15 Wis. Stats.
The weight table for use with vehicles not meeting the IoH or Ag CMV definitions is found in s. 348.15 (3) (c).
An example vehicle would be a truck tractor and semi-trailer with a hopper bottom being used to haul grain from on farm storage to a market location. Another example would be a truck tractor and trailer with a forage trailer being used to haul silage from a horizontal silo to a feed out location
Fines
Amount of overweight violation for IoH and Ag CMV is based on statutory limit in the s. 348.15 (3) (c) table, not the IoH/AG CMV allowance s. 348.15 (3) (g).
For example:
An IoH weighing 96,000 lbs. GVW was stopped by law enforcement without a permit. The violation is based on the maximum weigh limit of 80,000 pounds GVW. This IoH would be 16,000 pounds over the weight limit and fines would be assessed based on 16,000 pounds overage not 4,000 pounds.