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Lowering PSI for better ride?

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2500ltd

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Hey all. I tow a 4000 pound travel trailer with a 500 tongue weight using my 2021 Cummins 2500. I find the truck is bouncy on rough pavement even under load, ie trailer in tow and bed full of camping gear. I run 65 PSI all around as per the door jam sticker. Would it be safe to lower to 60 all around or less to try and make it a bit more stable? Or perhaps keep 65 in rear but lower front? Any advice to stabilize my rig? Thanks.
 
Check the tire chart for your tires and the load you are hauling.
Empty on my 21 PW with 35s, I run 40 front and 35 rear.
Even at 55, I could see that the outer edge of the tread was not even touching the ground. So way overinflated.
The 65 PSI on the door is for max weight, and even then it's too much according to the tire charts.
You can blame the lawyers and sue happy folks for that mess.
 
Greenhills said:
Stock tires? You can get away with 55-60 PSI. the tongue weight on that trailer is nothing.
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your ride at 65psi will be horrible, I lowered mine to 50 initially and the ride was do much better and when I changed my wheels/ tire I am now at 45/40 and ride is perfect. You need to lower the PSI and test it out, you will love the way it rides
 
Keep in mind that you have 20" rims with low-profile tires. You can't lower your psi as much as you could with 18" wheels with a higher profile tire.
 
matski said:
Keep in mind that you have 20" rims with low-profile tires. You can't lower your psi as much as you could with 18" wheels with a higher profile tire.
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You and I have vastly different definitions of low profile. I ran Michelin Pilot tires on 21” rims on a Tesla Model S P85D. Those were basically a rubber band around the rim. ;-)

I just lowered my RAM tires to 55. Can’t tell the difference visually. Going for a ride soon to test out.
 
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So I test drove at 55. I notice the difference. Am I pushing my luck if I lower even more? Here are my numbers:

Curb weight + me + wife + full tank +
camping gear = approx 8000 #.

Add tongue weight + 2 teenagers = 900

At 55 PSI, all 4 tires can support 11000 # (2775 each)

Gives a 19% margin.

At 50 PSI, all 4 tires can support 10400 # (2600 each)

Gives me a 14% margin.

Thoughts?
 
I'd drop to 45 if you still have some margin. Would probably ride better.

And I can guarantee the tire charts have some margin built in already.
 
After 4 decades of towing various set ups all I can add to the convo is, keep a check on your tire temps. I run stock pressure on my 3500 dually and tow heavy with no issues. I had a friend who towed a 5r pop out on lower 'comfortable' pressures and tore the skins off the rear tires. Lower pressures will yield much higher tire temps which could lead to tire failure. At the risk of upsetting some folk, if you want a nice, smooth, comfy ride, don't buy an HD truck.
 
Southernspeed said:
After 4 decades of towing various set ups all I can add to the convo is, keep a check on your tire temps. I run stock pressure on my 3500 dually and tow heavy with no issues. I had a friend who towed a 5r pop out on lower 'comfortable' pressures and tore the skins off the rear tires. Lower pressures will yield much higher tire temps which could lead to tire failure. At the risk of upsetting some folk, if you want a nice, smooth, comfy ride, don't buy an HD truck.
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We just finished a 2500 mile trip across 7 states with a 12k lb 5th wheel and my dually's rear tires never exceeded about 47 psi each. I kept the fronts at 70 because the front of this truck rides very nice as it is.

At some points in Nevada it was 107* outside.

Needless to say, tires were fine (even the cheap China may-pops that the 5th wheel came with). 0 issues whatsoever.
 
Southernspeed said:
After 4 decades of towing various set ups all I can add to the convo is, keep a check on your tire temps. I run stock pressure on my 3500 dually and tow heavy with no issues. I had a friend who towed a 5r pop out on lower 'comfortable' pressures and tore the skins off the rear tires. Lower pressures will yield much higher tire temps which could lead to tire failure. At the risk of upsetting some folk, if you want a nice, smooth, comfy ride, don't buy an HD truck.
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I’m actually generally fine with how the truck rides. Not really looking for more comfort. What I’d like though is to beat up my trailer a bit less. When the truck bounces on bad road surface, the trailer takes a beating and stuff gets loose. Screws come off, items fly around, etc. (Before you ask, my current trailer is light and doesn’t need an HD truck but the incoming one does.)

On the risk of blowouts from running the pressure too low, I have heard that a lot but is that still the case if you respect the OEM load and inflation chart? Why would they stipulate a tire pressure that strains the tire?
 
I think respecting the OE guidelines is fine unless someone buys remoulds or ChengShlingh budget crap that may need a bit more consideration. I know from customer's previous experiences and stuff I've seen in the trade that 'low' pressures can easily cause tire failure due to heat. At the very least, it can cause abnormal wear , where low pressure will wear the outer quarters of the tread far faster than the center area.
 
Southernspeed said:
At the very least, it can cause abnormal wear , where low pressure will wear the outer quarters of the tread far faster than the center area.
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That just means it's at the wrong pressure.
If I left my tires at the factory specs, the center would wear out and not the edges because they were over inflated for a empty truck. Even being 15 PSI under the factory recommended pressure of 65 PSI, I could still see daylight between the road and outer tread blocks.
That's why I'm at 40/35.
 
Crusty old shellback said:
That just means it's at the wrong pressure.
If I left my tires at the factory specs, the center would wear out and not the edges because they were over inflated for a empty truck. Even being 15 PSI under the factory recommended pressure of 65 PSI, I could still see daylight between the road and outer tread blocks.
That's why I'm at 40/35.
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Presumably you adjust your pressure every time you're loaded/hauling? I'm hauling as much as not so can't be doing with adjusting 6 tires each time.
 
Op here. Just completed a 1500-mile trip towing my TT with my 2500. All 4 tires at 55. Clear difference in handling of bad roads. Smoother. I also noticed less havoc and stuff coming loose in the trailer.

On the coolest day of the trip, the tires stayed below 60 as we drove and the handling was even better. I have room to lower to 50 based on the loading chart. Might try it.

Question, should I consider air bags to further smooth out the ride and effects on the trailer?
 
I'll just say this.

Comparing front tire pressures on a PW with 18" wheels and a Cummins with 20" wheels is apples and orangutans.

Get too low on the front and the weight of the mighty cummins will make it push and slow to respond.

As to adding air bags on a coil sprung 2500, they will help make the rear end more stable and give you some leveling capability, but I doubt you're going to make for a better ride.
 
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