Truck Capacities

December 2014

We did a significant amount of research before purchasing our 2011 Silverado 3500 Dually.  As I reviewed the RVing forums (thanks to all the posters from IRV2 and ESCAPEES Forums) & analyzed the truck manufacturers specifications, I found that the trailer weight one can actually tow (at least for a 5th wheel RV like ours) is SIGNIFICANTLY different than the towing capacities the manufacturers like to toss around.

Two potential problem areas quickly emerge when analyzing the specs:  Payload Capacity, Gross Combined Vehicle Weight, and Rear Gross Axle Weight Rating.

  1. Manufacturers typically base Payload Capacity on one 150# driver, a nearly empty gas tank, and nothing else in the truck or added to the truck.  I weigh over 150# and plan to take Judith in the truck too; I often travel with a full tank of diesel; I have a heavy duty 5th wheel hitch; I carry some tools; etc. etc. etc.  We very quickly consume close to 2,000# of the payload capacity before we even attach the trailer.
  2. The problem one encounters with Combined Vehicle Weight is generally related to the Payload Capacity problem.  If you have a truck with a “curb weight” of 7,000#, you add 1500 to 2,000# of payload, then you add a 16,000# trailer and your Combined Gross Vehicle Weight is now 25,000# against a Rating of 23,000#!
  3. Rear Gross Axle Weight Rating — When I figure that much of the above payload will be in the bed of the truck (or at least shared equally between the front and rear axle) and then I add the Pin Weight of our 16,000# (fully loaded max trailer weight) which is usually in the range of 20% of the total trailer weight.  One quickly begins to approach the rating for the rear axle.

Here are the results of one of the reviews we did before we decided on our truck:

My “new” truck capacity worksheet:     truck-trailer-worksheet

This spreadsheet is intended to answer the question “is it safe to pull my trailer with this truck?”  So it assumes you have a trailer & truck in mind.  The trailer towing specifications of each truck model changes from model year to year as the manufacturer modifies their design.  The manufacturer’s “towing specifications” can be found on the internet for each specific truck make and year — ie, 2011 Ford 250.

PDF of our analysis (our results):     Truck Capacities – Results

Excel Spreadsheet Download:           Truck Capacity Calculations – Excel Spreadsheet

For other aspects of making your decisions about RV Living, here are other posts on the subject:   RV Life & Technical Details


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