Air Pressure 19.5 tires

I agree with the 10psi of extra air, it's not enough to increase road hazard issues, or worse the ride but there will be added stability and the tires will be cooler.

Has anyone else noticed their 19.5s running warmer than LRE tires? Mine certainly do, not crazy hot but they are warmer. Adequate air pressure, verified with a scale, is in the tires.

There is a 3% weight correction factor for the Dynatrac verses Michelin if you use the above loading/inflation chart. At 110 psi, you are at the weight limit of the 4500 lb Vision rims and have no reason to go higher. 95 psi is about 4000 lbs per tire and 80 psi is about 3500 lbs.

I err 10 psi higher on inflation than my measured weight so I don't have to worry about my DW collecting rocks along the way...

Thanks i stand correct.

billyray50 wrote:
As in my earlier post showing new 19.5 wheels and Dyna Trac PD890 16 ply load G 19.5 tires

Just a note (as Bedlam also pointed out).. 16 ply is LRH. 14 ply are LRG.

Per your photos in the other thread you have 16 ply LRH tires, 4805 @ 120 psi. Most LRG tires are 4540 @ 110 psi.

ah64id wrote:
I asked Toyo about going lower than the min pressure with weight on their chart, which was 80 psi. They said I could go to 70 psi, but that was as low as I should go based on the bead staying seated. 19.5's, well any .5" tire, needs more pressure to stay seated. ...

This is my understanding for the reasons you state.

Wayne

I asked Toyo about going lower than the min pressure with weight on their chart, which was 80 psi (245/70R19.5 M608z LRG). They said I could go to 70 psi, but that was as low as I should go based on the bead staying seated. 19.5's, well any .5" tire, needs more pressure to stay seated. I have run them at 50 rear and 70 rear with no noticeable change in ride, 70 is as low as I go.

My front axle is actually lighter when towing than empty, but I like the high pressure for stability. I run 70/70 empty and ~78/94 when towing. 94 just happens to be where my pressure switch on my OBA cuts out. I will probably change it higher, but 94 is plenty of air for my weight. 95 psi is good for 4080 lbs, and so far the heaviest I have been on the rear tires is ±3600lbs.

dadwolf2 wrote:
Does that chart mean that if you don't need the full load capacity of the tire you can run as low a pressure that's on the chart? So it's safe to go as low as 75 psi with the 19.5 tire? Or could you go even lower if the truck is unloaded?

It absolutely means you run the psi as per the load on the tire. I question that any of us will have a load of 4940 pounds per tire. That would be 9880 pounds on one axle on a single axle truck.

It is safe to run 75 psi with the 19.5 tires (245/70 size). Keep in mind, the chart tells us that the 245/70R19.5 will carry 6780 pounds per tire (single wheel). That would be 13500 pounds per axle.

I question you should go lower. I think if you could, the manufacture would have included that data. It has been a long time since I have done the research, but as I recall the sidewall relative to the wheel design is a major factor in the minimum psi.

Please keep in mind, the chart is from Michelin, on the 245/70R19.5 tire. Different sizes will have different data. I think this chart is in line with the industry standard for this tire size, but I am not positive.

Reddog1 wrote:
Ideally, the tires should be checked cold. The manufacture realizes the psi will be higher when hot. Depending on their size, I bet you the psi is the same as mine.

Does that chart mean that if you don't need the full load capacity of the tire you can run as low a pressure that's on the chart? So it's safe to go as low as 75 psi with the 19.5 tire? Or could you go even lower if the truck is unloaded?

With my G rated tires I run 60psi front/ 55psi rear when empty. 75psi front/110 psi rear when heavy.

Thanks Reddog1.