lowering tire pressure

[penner]

When we travel to our fish camp up north the last 40 miles is probably the roughest, washboard road I have ever driven on . That includes the Dempster and the road to McCarthy/Kennicott. I am heading up again Thursday morning and I was wondering how much I can safely lower my tire pressure? I've never had the need to do it before. I have 275/65/18 10ply KO2,s on my truck. Thanks.

 

[dennis 221]

I run 23-28 psi tundra hawk 275 /65/18 nitto r.g.

 

[Jon R]

Some good advice and references in this thread:

https://www.wanderthewest.com/forum/topic/21846-airing-down-tires-with-camper-on/?fromsearch=1

 

[smlobx]

What truck do you have and what is the recommended tire pressure for it?

In “General” terms you should be able to reduce your tire pressure by about 50% if you drive slow enough, but I would try a little higher pressure first, maybe 25% reduction.

 

[craig333]

25-35 in my truck. I'll take the Jeep down to six but two men and a boy could lift it up if I lost a bead. Maybe even lower if I'm really stuck.

Back in the olden days when I had a different truck and I was towing the Jeep I wound up on a dirt road, It was raining hard and on an uphill section I lost traction. Being solo there was no way to unhook the Jeep. So I spent an hour in the rain (had to warm up after each tire) lowering the tire pressure on the truck. Really good feeling when you ease into the throttle and it starts moving!

Before that I had a two wheel drive truck which I drove down a steep rocky road to the river. The river was nearly dry and when I tied to leave I just spun the tires. Unfortunately I was probably about twenty and didn't know about airing down. Can't say if it would have worked but I bet it would have. Might have saved me a scary hike down the railroad tracks back to town.

 

[craig333]

Its pretty interesting how a few psi make a big difference. At 15 in the Jeep it feels very stable. 10 psi and it really feels mushy. I haven't figured the trucks sweet spot yet.

 

[rubberlegs]

We've gone as low as 15 psi front, 20 rear (E-rated tires). Sometimes when I'm feeling conservative, we'll do 20/25. But placard pressure (P-rated tires) is 30/30. On pavement we're running 47/62, so we're using about 1/3 pavement pressure.

I like the speed rule of thumb, ramblinChet! Great idea. Somewhere I saw a pressure vs. load chart for E-rated tires, but last time I looked for it I couldn't find it.