18psi on 37" Iroks when going light...15psi on the same when wheeling hard.
PSI on the trail
- Thread starter cgswimmer48-91
- Start date
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Had plenty of practice with 4-wheeler tires when younger, but I learned my lesson on fire from other sources of combustion. Just gotta make sure the wind isn't blowing and that you didn't get any fluid on your body.
No joke!
cartercd
SILVER Star
Here is what I said in a previous thread on this topic:
Since this is very specific to your particular tire and vehicle, I recommend developing a footprint versus pressure curve. I air up to full pressure and measure the tire footprint. I then deflate 5 psi and measure again, repeating the process down to 10 psi. I then plot a footprint versus pressure curve.
You will observe that the width of the footprint is relatively constant, but the length increases. You will also observe that the curve is not linear. Here are the results from my 285 Revos on a relatively stock weight truck.
Pressure/Area/% increase in area
40/ 82.0/ -
35/ 82.6/ 1%
30/ 85.9/ 5%
25/ 92.8/ 13%
20/ 102.0/ 24%
15/ 108.0/ 32%
10/ 127.7/ 56%
So for me airing down 10 psi only increases the footprint 5% (negligible), but the next 10 psi really starts producing results. I use this table as a guide based on the type of terrain I'm in and the traction I need. Keep in mind that you increase the risk of breaking a bead at very low pressures. Also, most tire pressure gauges aren't that accurate at low pressures, so having a low pressure gauge is a good idea.
Since this is very specific to your particular tire and vehicle, I recommend developing a footprint versus pressure curve. I air up to full pressure and measure the tire footprint. I then deflate 5 psi and measure again, repeating the process down to 10 psi. I then plot a footprint versus pressure curve.
You will observe that the width of the footprint is relatively constant, but the length increases. You will also observe that the curve is not linear. Here are the results from my 285 Revos on a relatively stock weight truck.
Pressure/Area/% increase in area
40/ 82.0/ -
35/ 82.6/ 1%
30/ 85.9/ 5%
25/ 92.8/ 13%
20/ 102.0/ 24%
15/ 108.0/ 32%
10/ 127.7/ 56%
So for me airing down 10 psi only increases the footprint 5% (negligible), but the next 10 psi really starts producing results. I use this table as a guide based on the type of terrain I'm in and the traction I need. Keep in mind that you increase the risk of breaking a bead at very low pressures. Also, most tire pressure gauges aren't that accurate at low pressures, so having a low pressure gauge is a good idea.
