Max Pressure Cold vs Hot Pressures - How Much Is Too Much

[Rollochrome]

My Carlisle CSL 16's have a cold max pressure of 110.

I installed a TPMS the same day I bought them.

I read up on these tires and there was nothing about a hot max pressure from Carlisle. I contacted Carlisle and they said there was no "hot max" specified.

So on the maiden voyage with them, I watched the temps rise and rise above 110 to just under 120.

The tires on the sunny side were uniformly higher than the ones in the shade side understandably too.

I read elsewhere that a different manufacturer emphatically states on their website regarding trailer tires to NEVER bleed down HOT tires.

So it begs the question, how much hot pressure is too much? The TPMS system instructs to set alert levels that are pretty high.

What do you think is an acceptable pressure level hot relative to the cold max?

[Cummins12V98]

MOST RV's use the tire capacity as it's weight limits so it goes the tire should be filled to MAX psi because that is what the RV will weigh fully loaded.

[Cummins12V98]

fj12ryder wrote:
If I ran my old trailer with tires at the max, I would have the capacity for nearly 24,000 lbs. on the triple axle. Having weighed the trailer, I knew I had barely 15,000 lbs. on those six tires. Absolutely no reason to run max pressure, and suffer the resultant rough ride.

Don't forget uneven tread wear and less stopping ability!

As I keep repeating "there is a reason for the weight/inflation charts"

[noteven]

My Big Fiver tires are Q rating 99 mph. I have a time getting it going that fast.

[MFL]

fj12ryder wrote:
If I ran my old trailer with tires at the max, I would have the capacity for nearly 24,000 lbs. on the triple axle. Having weighed the trailer, I knew I had barely 15,000 lbs. on those six tires. Absolutely no reason to run max pressure, and suffer the resultant rough ride.

Since a triple axle adds a lot of capacity to a trailer, I am just curious, if your previous trailer came with those tires rated to carry 24K. Did you upgrade from the OEM tires listed on the TH placard on the driver's side front?

Anyway, JIMNLIN, ^^^ and I are on the same page, when considering a RV trailer, outfitted with the proper ST tire.

Jerry

[JIMNLIN]

Rollochrome wrote:
Lots of good opinions here. I appreciated the feedback on this thread.

Your tire mfg "Goodyear" says this about tire pressures used on trailers; clicky link
Goodyear Tire and Rubber .... weighing RVs
Special Considerations

**Unless trying to resolve poor ride quality problems with an RV trailer, it is recommended that trailer tires be inflated to the pressure indicated on the sidewall of the tire. Trailer tires experience significant lateral (side-to-side) loads due to vehicle sway from uneven roads or passing vehicles. Using the inflation pressure engraved on the sidewall will provide optimum load carrying capacity and minimize heat build-up.**

Of course Goodyear assumes the trailer has properly matched tires/wheel for the trailer...and hasn't been over tired as some rv trailer owners have done like using a load G at 4400 lbs capacity on a trailer with 2600-2700 lb load on the tires.

[time2roll]

fj12ryder wrote:
If I ran my old trailer with tires at the max, I would have the capacity for nearly 24,000 lbs. on the triple axle. Having weighed the trailer, I knew I had barely 15,000 lbs. on those six tires. Absolutely no reason to run max pressure, and suffer the resultant rough ride.

Not very common from the posts I read. Most trailers have the minimum or a bit less if they can. GVWR stickers frequently recommend sidewall max for trailer tires.

Nothing wrong with adjusting based upon weight either. Still I would be 5psi over the chart not to exceed sidewall max. No harm to the tire running max psi. Could be a bouncy or harsh ride is all.

[fj12ryder]

If I ran my old trailer with tires at the max, I would have the capacity for nearly 24,000 lbs. on the triple axle. Having weighed the trailer, I knew I had barely 15,000 lbs. on those six tires. Absolutely no reason to run max pressure, and suffer the resultant rough ride.

[Rollochrome]

Lots of good opinions here. I appreciated the feedback on this thread.

[Sjm9911]

I always fill to max cold, im not weighing my TT everytime i load up for a trip. And each trip is diffrent. So, sometimes inflatable yacks, sometimes more gear for a longer trip. But im not weighing each time to set tire pressure. Of you travel where temps change dramatically, just recheck the tire pressure before you set off in the morning.

[MFL]

^ Agree, simple is good!

Normally, an OEM RV trailer tire has just enough capacity to cover the trailer weight when it is fully loaded. That capacity is usually at max sidewall psi.

When things change, is when the owner decides to go up in rating/capacity/higher psi max. One size, say D rated to E is a good thing if D is right at the edge. In this example, on an ST tire, you still can't go wrong with max pressure, or close to it. The problem comes, when the owner thinks he should change from Ds to Gs, and use only 2 thirds of max. A heavy tire, with low psi is going to have more rolling resistance, and run hotter.

Jerry

[Campinghoss]

Folks worry way too much over simple things. Rving is suppose to be fun and exciting. I have been pulling for 50 years. I always set my tires to max inflation as the tire states. I may be jinxing myself but the only tire trouble I have had was the valve stem failed while I was backing into a site and the tire went flat. I expect a lot of tire failures are due to under inflation and the tire running too hot.
I am not knocking those who weigh, adjust psi regularly just expressing my thoughts.

[Cummins12V98]

JRscooby wrote:

Cummins12V98 wrote:
Over/under MAX has nothing to do with "PROPER" inflation. There is a reason for every tire there is a Load/Inflation chart.

Weigh your axles and add 5psi to what the chart recommends. This is per GY Tech support for when a person wants to use the brain GOD has given you instead of blindly airing to MAX sidewall pressure.

LOL. "Proper inflation"? Weigh axle, check chart. If the tires on the axle are equally loaded, that 5 lbs is over inflation. OTOH, if you have a 30/70 split, you could still have a tire underinflated.

Hey run MAX I don’t care but there are people that like to use the brain GOD gave then.

[laknox]

Rollochrome wrote:
My Carlisle CSL 16's have a cold max pressure of 110.

I installed a TPMS the same day I bought them.

I read up on these tires and there was nothing about a hot max pressure from Carlisle. I contacted Carlisle and they said there was no "hot max" specified.

So on the maiden voyage with them, I watched the temps rise and rise above 110 to just under 120.

The tires on the sunny side were uniformly higher than the ones in the shade side understandably too.

I read elsewhere that a different manufacturer emphatically states on their website regarding trailer tires to NEVER bleed down HOT tires.

So it begs the question, how much hot pressure is too much? The TPMS system instructs to set alert levels that are pretty high.

What do you think is an acceptable pressure level hot relative to the cold max?

I've seen temps on my fully-inflated E range tires approaching 150 on the sunny side, and that was loaded to well below the 11,360 GVW on my old Komfort, which was placarded for D tires. I run +/- 62 mph, so speed's not an issue. These tires are built for this, so just run 'em and check them daily. Get a temp gun and check them first thing when you stop. Check your truck tires, as well, and don't forget the hubs.

Also, if you tend to run well below your GVW, personally, I'd have zero issues with running at 100 psi. With the above-mentioned Komfort, I'd run 70-75 psi most of the time and only go to 80 when I was heavily loaded. Given that the rig was placarded for 65 psi D tires, I was well within load specs.

Lyle

[MFL]

I think some of the tire inflation, disagreement, is due to talking about many different types of tire use. What works for cars, trucks, DRW trucks, motorhomes, and trailers, is not comparing apples to apples.

Most put the proper tires on their tow vehicle, and adjust as needed for load. I see some people buying way more tire than their trailer needs, then reducing pressure, way below max, when they should have just purchased the proper tire needed for the load, and aired for the load.

Jerry

[way2roll]

Rollochrome wrote:

way2roll wrote:
Curious why you are setting to max. Your FW should have a recommended psi .

It does. It came with F rated tires that had a max psi of 100

I replaced them with G rated tires that have a max psi of 110 so I went with the tires max psi rather than what the trailer sticker specified based on the factory equipped tires

Ok, makes sense. Then your best option would be to follow the inflation chart from the manufacturer of your new tires.