Tire Pressure advice.

[Sander]

I had a shop mount new 33x12.5x15 all terrains under my 77K5. The guy put them on 32psi. I get the idea that that is too high. He told me it should be on 32. Could anyone advice me on the pressure I should drive on? The K5 is about 5500lbs.

Thanks in advance.

 

[Capt.D]

I worked at a tire shop years ago and that's exactly what I ran in my 33's. Lasted a long time as well. You can air down if you go in mud or sand to get a wider footprint but I would air back up on the road.

 

[chulisohombre]

look at max load rating on the tires and if your rig weighs 5500 it is usually a 60% front 40 % rear weight difference and do pressure according to that.i run mine at 30 front 25 rear but they are load range d with i think 3500 pounds max appiece load ratingyou just dont want the tire to balloon where just the center of the tire is in contact with the road surface.you can also draw a chalk line across the tire and run it a quarter mile and see where the chalk line rubber off.it will tell you if the air is correct or not if the chalk line is wore off the same all the way across the tire.

 

[Thunder]

I run 28-32 in my 33s for road duty.

 

[4X4HIGH]

That sounds about right. I run 35psi in my 35" BFG's on a 6000 pound rig and i get 50K+ miles on a set of tires.

 

[frikenwoodro]

Take a piece of chalk and drawl lines across the tread of the tire drive about 10-15ft ish and if the line wears even leave them. If the center wears more air them down. If the side walls wear down more add air.

That's the way I do it when its in question . But most of the time the tire manufacture will have the suggested amount of pressure for the particular tire.

 

[K5dreamer]

32psi is pretty much the "nominal" balance of ride comfort, handling, and economy. which is why most car companies have you air tires up to around that level.

I run 40psi in my tires 33x12.50-R15's. which i feel helps me get 22mpg on the highway

I also run 42psi in my jetta, ride is still smooth, i get 44mpg commuting, and up to 65mpg on the highway. get a little squirrly at about 90mph.

 

[Kenny78]

post 3 and 6 is how I set my tires.

 

[chulisohombre]

post 3 and 6 is how I set my tires.

this is the easiest and most effective way to set up any tire for any oversize vehicle.cars are a different story.those tires i always run at 35 as per the sidewall as they are almost always rated for cars and best stability at that rated pressure.