Tire Pressure Question

[Cdburgerjr]

I have the same feeling. Sure seems low. But, the chart presumably is saying for my actual load with my actual tire that the indicated PSI (40/50) is big enough to avoid flex and small enough to avoid center wear, maintain maximum road contact, yada yada. If I load it more, I should increase PSI. The tire load at max PSI is more than the rest of the truck can handle.

Part of my question is why does half the Internet say “look at the load tables” and the other half say “don’t trust the tables”? What is the real value of the manufacturer table?

I was happy to find the Ford tire weight/PSI sticker agreed with the table. So my real root question is, since my actual weight is less than sticker, shouldn’t the PSI be too, per the table?

[BobLandry]

I run everything at max cold pressure as shown on the tire, air them cold, and get 70K out of Michelins. I'm not going to mess with success.

[Scott'n'Wendy]

I run everything at max cold pressure as shown on the tire, air them cold, and get 70K out of Michelins. I'm not going to mess with success.

Exactly. Max pressure is max tire strength. Springs do more than tires for ride. I can't tell the difference in ride in my truck between 70 or 80 psi so it's 80 all the time. Loaded or unloaded. Never had them wear unevenly across the tread.

[BobLandry]

And the higher pressure allows for less flexing of the sidewall and the tire to run cooler, which IMHO is harder on tires that any other factor beside running under-inflated.

[Cdburgerjr]

I received the following from the Michelin customer support website answering my question about PSI and load tables.

Good Morning Douglas

Thanks for contacting the Michelin Consumer Care Team. My name is Chris and I look forward to helping you out. You've been assigned case number xxxxxxxx. This will allow my team to quickly pull up your case details if any further questions arise.

You wouldn't put the max pressure in the tire cause that would a over inflation and could cause issues with the tire. As far as the PSI you would put 40 in the front and 50 in the rear as you stated.
…
We appreciate your business and thank you for choosing Michelin.

Sincerely,
Chris
Consumer Care Department
Certified Michelin Product Expert

[DECelt]

I received the following from the Michelin customer support website answering my question about PSI and load tables.

I've been towing heavy trailers for a long time and that is not a response that I would put much stock in.

As others have said, WHEN TOWING, the listed sidewall PSI for max carrying capacity (both truck and trailer) is where you want to be unless you want to go through the process of weighing each tire at full load, adding a safety margin and then determining the pressure from there....but that's a process and not one that many people want to get involved in.

There are significant road forces at play when towing, and any shift in weight (cornering) can dramatically increase the weight on one side or one tire.... (Think top heavy, swaying trailers) IMO, having too little excess tire carrying capacity, combined with dynamic weight shifts and too low tire pressures is the main reason for catastrophic tire failures. And as others have said, less air means higher tire temps etc. and these excess forces are cumulative. A little damage here, a little damage there....

In case that isn't enough...higher tire pressures decrease the risk of rollovers in emergency manuvers (I was an emergency vehicle driving instructor....lots of long days on closed airport runways [emoji38]).

If I had to pick a rougher ride (which I am not convinced is an issue towing a trailer) or maximum load capacity, I would go for load capacity every day when towing a trailer.

When daily driving, I tend to follow the recommended pressures on the vehicles doors.

Just my opinion....but an opinion with lots of experience.

Good luck and enjoy!

Sent from my moto g power using Tapatalk

[BobLandry]

Rough ride, if it is even discernible, is not a factor with me either. After all, it is a truck. If you expect a Caddilac ride, buy one. I'm more concerned with safety and tire durability/longevity than getting a soft ride.
Max cold pressure is not an issue either. Tires are engineered to withstand the heat build-up when running at max pressure. I don't understand why anyone thinks less contact between tire and road, afforded by running max pressure, doesn't contribute to tire life and safety.

[JKellerJr]

Running over inflated does not increase your contact patch it reduces it. If your running higher pressures that the load requires, your running over inflated. Will it hurt, probably not, and absolutely under inflation is way more dangerous that over inflation.

We have Michelin, one of the most respected tire manufactures in the world stating, in writing, to run pressures based on load. There are inflation load tables out there from every tire manufacturer telling us what to run. The ones who actually design, test, and get sued if their wrong.

Below is an article about this very thing from a commercial perspective, who run heavier and longer than most of ever will come close too. Now you could argue that that's commercial tires not what were running but since it pretty much aligns with what the email from Michelin says and the inflation tables we have access too, I think it probably applies.

Personally, I'm not gonna tell you what to run, do your research and make your own decision based on your circumstances. I actually do both. I tend to leave my rear tires on my truck at 80(max). I pull and haul often and when loaded, am close to the tire max rating. I don't want to continually be changing the pressure. When I put the the RV away for the winter I'll lower the pressures as I don't run loaded much at all over the winter and snow traction is much better at lower pressures. On my trailer though, I run at the load tables rating with a little extra to account for uneven loading.

I doubt over inflation, in the amounts we are talking about here and the distance we travel, with hurt anything. Will it help, the evidence seems to say no. But if it gives you more confidence/comfort than by all means run it up to max. Confidence and comfort is probably worth than anything.


https://www.truckinginfo.com/153054/the-magic-number

Particularly interesting (bolding mine):

“We experience much less tire wear and casing damage than I hear other fleets complaining about,” he says.

The key, Miller says, is the ability of the slightly softer tire to flex the way it was designed to.

“We had almost no impact damage in all those years, and we saw none of the irregular wear that a lot of fleets complain about,” Miller says. “Those problems come from tires that are too hard to function the way they are designed to function – that is, having enough give in the casing to absorb impacts like potholes and road debris, and having the optimum footprint or contact patch.”

[Hoopy Frood]

I have read similar statements before: that too high pressure doesn't allow the sidewalls to flex enough and the force of a big pothole, bridge translation, or similar can possibly cause damage to the sidewall. Just what I've read in the past. I run my tires based on load. It does seem to make the truck ride smoother with less violent bounces over some of these really rough roads.

[The_Lovells]

No, that's what the sticker says anyway. I run my at 80 in the back and 70 in the front all the time loaded or not.

That seems wrong two have two different pressures on your 2021 Solitude 375 RES-R