Predicts Axle Weights and Receiver Torque when using a Hitch Extension  V1.3

Step 1:  Enter Truck Information

GVWR:
Combined GCWR:
Front Axle (GAWR):
Front Tires - Max Loading:
Rear Axle (GAWR):
Rear Tires - Max Loading:  

  Hitch Receiver Rating:
Max Tongue Weight (TW):
Maximum Trailer Weight (GTW):

 

        

 Notes:

  1. Tire load rating can be found on tire sidewall.

  2. Tire maximum loading will be lower when tires are used in DRW configuration.

  3. Receiver Ratings are marked on receiver. 

 Typical Hitch Ratings:

  • Class I - 200 lbs Tongue Weight, 2000 lbs. Gross Total Weight

  • Class II - 350lbs Tongue Weight, 3500 lbs. Gross Total Weight

  • Class III - 500 lbs Tongue Weight, 5000 lbs. Gross Total Weight

  • Class IV - 750 lbs Tongue Weight, 7500 lbs. Gross Total Weight

  • Class IV (Weight Distribution) - 1200 lbs Tongue Weight, 12000 lbs. Gross Total Weight

  • Class IV/V - 1000 lbs Tongue Weight, 10000 lbs. Gross Total Weight

  • Class V - 1200 lbs Tongue Weight, 12000 lbs. Gross Total Weight

  • Class V - 1400 lbs Tongue Weight, 14000 lbs. Gross Total Weight

  • Torklift Superhitch - 600 lbs TW, 6000 lbs. GTW (with 48" Extension)

  • Torklift Superhitch (Weight Distribution) - 1200 lbs TW, 12000lbs. GTW (with 48" Ext)

  • Reese Titan (Weight Distribution) - 1800(?) lbs TW, 18000lbs. GTW

Step 2 - Enter Actual Values (without trailer)

(A) Front Axle Weight (lbs):  

(B) Rear Axle Weight (lbs):  

(C) Wheelbase (inches):  

(D) Rec'r to Rear Axle (inches):  

(E) Hitch Extension (inches):  

(F) Tongue Weight (lbs):  

(G) Loaded Trailer Weight (lbs):  

  
Step 3:  Calculate Results

                

DISCLAIMER: The calculations in this document have NOT been engineered nor reviewed/approved by a professional engineer. The calculations and information provided may contain errors and MUST NOT BE USED without reference to manufacturers published specifications. Although this calculator is in the public domain, no guarantee is expressed or implied that it will serve the purpose intended.
Definitions:
GVWR
  • Gross vehicle weight rating. The value specified by the manufacturer as the maximum allowable loaded weight of the vehicle.

GCWR
  • Gross combination weight rating.  The value specified by the manufacturer as the maximum allowable loaded weight of the truck, camper and trailer.

GAWR (May be regulated by State/Provincial Regulation)
  • Gross axle weight rating.  The value specified by the manufacturer as the maximum loaded weight on any single axle on the vehicle.

Tire Ratings (May be regulated by State/Provincial Regulation)
  • The value specified by the tire manufacturer as the maximum allowable load that can be put on each tire.
  • Dual tires mounted on the rear axle will have a lower rating than the same tire mounted on the front axle.
  • The maximum permissible load varies with the cold inflation pressure.  Consult the manufacturers data for specific values.
  • Do not operate above the maximum pressure stamped on the tire sidewall.

Maximum Allowable Tongue Weight
  • The value specified by the manufacturer as the maximum allowable trailer tongue weight that can be carried by the truck hitch receiver using a Standard Ball Mount.
  • Can be found stamped or on a label on the receiver.
  • Ensure that the ball mount has the same rating as the receiver.

 

Maximum Allowable Trailer Weight
  • The value specified by the manufacturer as the maximum allowable trailer weight that can be attached to the hitch receiver.
  • Includes both the weight on the trailer axles and the tongue weight.

 

           

 Receiver Torque
  • The torque (rotating force) applied to the hitch receiver by the hitch extension.
  • The torque increases proportionally with the length of the  extension.
  • Typically, the manufacturer will not publish torque limits, but may provide ratings with extensions of specific lengths.
  • This calculation can be ignored if the manufacturer specifies a rating with a hitch extension.  Torklift Superhitch provides ratings with their extensions.
  • Torque can be significantly reduced through the use of a weight distribution (equalizer) hitch.
  • A weight distribution hitch MUST be used any time the torque exceeds 110% of design.

Effect of a hitch extension on the maximum allowable tongue weight for standard receivers:

Note:  Does not apply to Torklift Superhitch or Reese Titan.  Offered for info only.  Always refer to manufacturers recommendations and specifications.

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