Tow Vehicle Tire Pressure

nagel wrote:
Do others increase / decrease the tire pressure in their tow vehicle when they are pulling the trailer? My truck specs say 35 psi for all 4 tires, but nothing about adjusting when towing.

What are you towing? Something short & light or long & heavy? Must have a 1/2 ton? P rated tires aren't very good compared to E rated, esp. as you get into longer and heavier trailers. For towing you want stiffer, not Cadillac soft. 35-40 psi is Cadillac soft and will result in more sway/poorer handling.

Recently got a '12 GMC Sierra 2500. Sticker says pressure should be 80 psi on the rears and 65 front. I'm using 75 psi on the front.
We put a set of LRE Goodyear Wranglers on it which have stiff sidewalls with a kevlar belt. We tow a 29' 7K lb TT. The truck tows the TT as if it was on rails. Zero sway. I never thought towing could be so good!

Had an F250 for 7 years, towing the same TT. It had LRE Michelins on it and ran 80 psi rear & 75 front. Sidewalls are a lot more flexible compared to the Wranglers. I thought that towed pretty good, but wow, the Sierra tows so much better. Difference has to be in the tires and maybe the heavy duty trailer package on the Sierra.

When I first got our F250, I experimented with different pressures on the front & rear tires and settled on the 80 rear & 75 front for best handling & sway control. Can't recall what Ford said the psi should be but was a fair bit less than this. Some people are shocked at running such high pressures but only downside is maybe a harsher ride which doesn't bother me in the slightest. I reduce the pressure over the winter months.

FWIW, tire pressure in a TV is just one of a number of factors to consider when looking at reducing sway and improving handling, and they all work together as a "package".