A trailer.
Question About Tire Inflation Presuure
- Thread starter antelopedundee
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antelopedundee
Well-known member
The door sticker for my vehicle says 35 PSI front and back. I thought that there might be a rule of thumb something like if you go from 2 ply to 8 ply add x PSI. Carrying a 1 ton load 80 miles one way needs a different pressure than making the same trip back empty.
FWIW I checked em out and bumped to about 40 PSI.
FWIW I checked em out and bumped to about 40 PSI.
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That 80psi on the sidewall is only for when the tire is carrying the max load. When not loaded there is no need to keep them inflated to the max psi. You'll only rattle your teeth out and wear the tires prematurely in the center.
I have had various E-rated tires on my 1500 for 20+ years and unless I'm towing with it the tires stay inflated to 40psi all the time. The tires always wear quite well.
I have had various E-rated tires on my 1500 for 20+ years and unless I'm towing with it the tires stay inflated to 40psi all the time. The tires always wear quite well.
Pump them up close to max.
elkhnter
Well-known member
Don’t want to highjack this thread, but want to throw this out.
Picked up a 2025 F350 a couple weeks ago. Got home and checked the tires. Front were 60, rear at 80. Put them all at 80 then checked the door. It said 60 and 80. Any ideas why?
I’ve always ran the same front and rear.
Picked up a 2025 F350 a couple weeks ago. Got home and checked the tires. Front were 60, rear at 80. Put them all at 80 then checked the door. It said 60 and 80. Any ideas why?
I’ve always ran the same front and rear.
cya , covers the max load and partial tire wear. But dumb.
I've always kept the same pressure front and back, unless I had a extra heavy load.
I found 20lbs under max out here in no where land to be good balance on wear.
I kept max or near when I was working and around pavement. That's working, not a costco run.
If you really want to get your contact patch correct there’s a method involving a parking lot (or long driveway) and some sidewalk or straight line chalk. Look it up and give it a go. Actual PSI in the tires is going to change a bit depending on air and run temperatures. So get them warm first.
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Uh no, there a reason tires are checked at cold psi.
Well, whoops I stand corrected. Always a good idea to read up on some random chit you see online before putting it into practice.
The chalk method still works for finding optimum contact though. I’d still recommend reading some other sources on the subject to OP.
What motor?
elkhnter
Well-known member
7.3
That motor isn’t near as heavy as the 6.7. That’s probably why the tire inflation is different. If you’re empty in back and not towing I don’t think I’d run 80…
antelopedundee
Well-known member
In chatting with my local tire shop guy he says that tires should be inflated to doorpost values regardless of ply type. I suppose that 2 ply tires have about the same wall thickness as 8 or 10 ply tires, but somehow I was thinking that thicker walls required higher pressures.
Nick87
Well-known member
This thread is entertaining to say the least.
Blue Steel
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I ran a ‘05 Ford f150 extended cab with various E rated tires including toyos and wranglers, no load or towing usually 38 psi summer and 32 psi winter better traction. I think door sticker said 38. Normal width/offset wheels and all tires lasted a long time, but i also use a portable battery air compressor to go up or down as needed.
You can certainly tell a difference in traction on snow or even wet pavement if you have too much air. I’d rather have less air than more.
When I see people’s online reviews of a well known high end tire that they say sucks in snow or on wet roads and they almost died one time, I wonder if their dealer or oil change place had read the “maximum 80 psi” (or 44 or 51 for SL or XL rated) and filled them to that.
You can certainly tell a difference in traction on snow or even wet pavement if you have too much air. I’d rather have less air than more.
When I see people’s online reviews of a well known high end tire that they say sucks in snow or on wet roads and they almost died one time, I wonder if their dealer or oil change place had read the “maximum 80 psi” (or 44 or 51 for SL or XL rated) and filled them to that.
russelldprice
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- May 30, 2025
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That will work just fine. I would probably run 38-40
My diesel F350 calls for 60 psi front as well.
Here's the deal jacks:
Door jamb sticker calls out tire pressure recommended for your factory tire/wheel combination for the maximum front and rear axle weight ratings. In most trucks, your rear axle is rated to carry more of your GVWR than your front axle, hence the 80 psi in HD trucks.
You can look up the specs for your specific tire from the manufacturer that will give you the load rating vs. PSI curve. I believe this is generally for sustained highway speed. You can run lower PSI for shorter distances traveling lower speeds.
Here's from a quick Google (for RV tires): https://www.yournexttire.com/trailer-load-inflation-char t/
antelopedundee
Well-known member
Running longer than I expected for sure.
