Towing tire pressure

Quick question: when towing, do you increase the pressure in your tires? If so, is there a standard formula, or something, that will tell us what the tire pressure should be based on what you're towing and how heavy it is?

I've just been ensuring the tires were inflated to the recommended pressure, but recently heard that I should bump it up when towing. I've only been towing for a month, so I'm new to it and don't know what the right answer is. Any help is appreciated.

 

I vary my tire pressure, depending on load, speed and terrain.

The rule of thumb for tire pressure is
that for every 10 degrees in temperature change,
from whatever the temperature/PSI is when you inflate the tires unladen,
will equal 1 lb/psi increase in each tire.

This can also apply to the rear tires of the hauler.
As the PSI may need be increased slightly due the trailer's additional tongue weight

Keep in mind your trailer has a weight carrying limitation designated by the Mfgr.
And so the Mfgr's determination of their trailer's limitations will need be taken into account (followed).

Recommended tire pressure determined by..? the trailer's Mfg'r ?

You should never exceed the maximum PSI designated on the side wall of the tire.
The tire's air pressure will likely need be set at it's max. when fully laden.
But tire PSI can/should be set lower when the trailer is unladen.

The various available ply ratings of a tire's construction will determine what weight can be carried on any particular trailer.
Not to exceed the Mfgr's max load carrying capacity of their particular trailer.
Most trailer Mfgr's install tires that meet - exceed their trailer's requirements.

But the tire pressure may need be set to it's minimal PSI rating (Mfgr recommendation)
when unladen, so that the trailer will roll with more control and less possible bounce.

Every trailer manufacturer establishes guidelines as per their particular trailer's weight and load capacity.
Because you did not share your trailer's Mfgr specifications...
It would be impossible for anyone to make determination/recommendation for your particular circumstance.

Towing PSI Read

 

Thanks for the response. I am smart enough to know never to exceed the max tire pressure as noted on the sidewall. My tires are rated at 44 psi max. I usually run mine at 33-35. I think I'll try them at 40 when I'm towing next time. See if that helps.

 

Load carrying capacity increases with tire pressure, so try the tires up near their max pressure and see how they perform. You can certainly do rough calculations based on the max load capacity of the tires you have, the weight of the trailer load, and the tongue weight. Some good towing info:

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=55&
https://www.etrailer.com/faq-weightdistribution.aspx