Max Load - Max Inflation & Cold Inflation confusion continues

From an RV Forum "My understanding is that the number on the side of the tire is not a recommendation. Rather it is the maximum cold temperature that the tire is rated for. You should never run above that number. Without actual weights, I would run the recommendation from the motorhome manufacturer on the placard near the driver's seat, or a little higher, but never over the sidewall number."

The information on the tire sidewall is a statement of the maximum load capacity and the cold inflation required to provide that load capacity.

Different tires have the word "max" placed in different parts of the phrase which leads to the confusion.

Here is a post on passenger tires.

Here is a post on when the Minimum inflation is the Maximum.

Note: A a statement of Max Load "At" stated inflation such as "Max load 3,000 lbs at 80 psi" is leaving off the implied "minimum" before the 80 psi.

Also introducing the word "cold" seems to confuse some.

Maybe this will help:

Tire inflation should only be set when the tire is at ambient temperature and has not been warmed by being in sunlight or driven on for the prior two hours.

A tire may be loaded to the number of pounds stated on the sidewall, only when the tire has been inflated, when cold, to the stated pressure on the tire sidewall.

The problem is that these phrases don't fit in the same place as current "Max Load 3,000 lbs at Cold inflation 80 psi"

Do your Tow Vehicle and Trailer match?

Here is some good advice I found on the Interweb and agree with.

Here is a short video from the RV Safety Education Foundation. A longer in-depth video link available at the end of this post.

 You should always do your calculations based on the GVWR of the trailer, not the dry (shipping) weight. The dry weight is a number used by some manufacturers and some dealers to try to sucker people into purchasing a trailer that is too much for their truck

The same goes for tongue weight. The marketing brochure may provide the trailer weight based on the empty trailer (with no propane or batteries, etc.). You should figure your weight based on 15% of the GVWR of the trailer. But the real trailer weighs figure you should know is what the truck scale tells you once the trailer is fully loaded but not hooked to the tow vehicle.

You can not use the "paper" figures found in truck or trailer literature and certainly not the verbal information from the truck or trailer salesperson to calculate your towing capacity. You MUST have real numbers which mean actual scale weights.

Next, take the cargo capacity of your truck (from the payload sticker from the door jamb of the driver's door on the truck). It will say something like "cargo must not exceed ... lbs.". From this payload capacity, you need to be able to deduct all of the following:
- People in the truck
- Cargo in the truck
- Weight of the WD trailer hitch or of the hitch for the 5th wheel
- Total actual weight of the trailer


Then you should also consider the maximum or gross combined weight rating (GCWR) - this is the maximum weight you're allowed to have on the road, which combines the full weight of the truck and trailer combined. To get these, you can use the GVWRs of both the truck and trailer, but really you should go to the scales and have them weighed as YOUR truck and YOUR trailer almost certainly do not weigh what is shown in the literature.

When working all these numbers, you need to consider the following:
- Do I have enough truck (engine, transmission, etc.) to pull this load up and over the hills without causing undue stress on the engine/transmission, etc?
- Do I have enough truck (brakes) to stop this whole load in the event the trailer brakes fail without causing undue stress to the truck brakes?
- Do I have enough truck (suspension, tires, etc.) to control the trailer in heavy winds, while passing or being passed by semi trucks - and especially in the event of an emergency maneuver, like dodging a deer which just jumped out on the road in front of me or a tire failure (blow-out).
I hope you're getting the basic information before you purchase. You'd be way ahead of the game.


In-depth video at RVSEF web site on truck - trailer matching HERE.

##RVT897