yesss, another tire pressure question (sorry)

[LandKKnight]

I know this topic has been discussed ad nauseum, and I have searched the forum but I can't find the succinct answer I'm looking for, yes, its about tire pressure (again). Is the consensus that you fill to the amount listed on the yellow sticker on the coach door jam, not to the pressure listed on the tire? We have a compressor that is supposed to fill to 100psi but seems it won't fill the tires past 80 and the sticker says 95 so we have to do it at a truck stop or something. However, aren't you supposed to do it when the tires are cold? So if you stop on the road, and the tires are hot, what to do? Thanks!

[SeaDog]

Max sidewall pressure normally applies to ST tires. Your rig has a different type of tire and should be set cold to the Mfg recommended pressure if you are running the Mfg supplied tires. Also that type of tire usually has two max psi settings one for single and one for dual position use. Some coaches have a chart for tire pressure according to GVW. Your option would be to get a different compressor or plan your day to start out by a place that can fill your tires when cold.

[johnmbeard]

The answer to your problem is buying a compressor that will do the job. You then might consider an investment into a Tire Pressure Monitoring System (TPMS).

[FOURWHL]

The correct answer is get your rig weighed and find the table for your tire manufacturer and fill to the pressure prescribed for that weight by the manufacturer of the tire. Any other methods are just less accurate guesses at achieving this. You can fill to max pressure to err on the safe side but your going to be making noticeable sacrifices in ride quality

[5picker]

Your rig is not a trailer so that may be why some of the other threads didn't address your question.

The air pressure information on the yellow sticker is the recommended pressure for the load your rig can haul as long as you have not replaced the tires with something different.

Yes, tire pressures are to be set when the tire is cold so stopping at a truck stop in the middle of a travel day is not the way you want to air your tires.

As mentioned, get a compressor that will do the job or find a place with a compressor where you can leave your rig sit long enough to check the pressures cold.

[LandKKnight]

Originally Posted by johnmbeard

The answer to your problem is buying a compressor that will do the job. You then might consider an investment into a Tire Pressure Monitoring System (TPMS).

Thanks, everyone. Turns out DH had the compressor set to max 80psi. When he discovered this, he reset it to 100 and was able to inflate to 95. On our sticker, both front and rear say the same, 95psi, so that's what we'll do to start out, but I really want to get our rig weighed anyway, to make sure we are actually within ccc. Then we can find the charts and do the calculations like it has been suggested.

[extremebike]

Originally Posted by FOURWHL

The correct answer is get your rig weighed and find the table for your tire manufacturer and fill to the pressure prescribed for that weight by the manufacturer of the tire. Any other methods are just less accurate guesses at achieving this. You can fill to max pressure to err on the safe side but your going to be making noticeable sacrifices in ride quality

x2

[halla]

Originally Posted by LandKKnight

Thanks, everyone. Turns out DH had the compressor set to max 80psi. When he discovered this, he reset it to 100 and was able to inflate to 95. On our sticker, both front and rear say the same, 95psi, so that's what we'll do to start out, but I really want to get our rig weighed anyway, to make sure we are actually within ccc. Then we can find the charts and do the calculations like it has been suggested.

Sometimes it is the little things that make the easiest fix.

[windsurfdog]

Also be aware that if you move up to a higher rated tire, recommended pressure will normally increase. I moved from a C rated tire with 50 psi recommended to a D rated tire with 65 psi recommended. The C rating is what the yellow sticker says. To utilize most of the extra weight carrying capacity of the new tires, I run them at 60 which also gives a bit less bouncy ride. So the yellow label should not rule in cases like this.

[ckabrahamson]

Another important point about setting your tire pressure...

After weighing your rig and looking up the needed pressures for the specific tire manufacturer and model tire, measure the "cold" pressure early in the morning and out of the sun... Sun shining on the tires will cause a significant pressure increase.

Also, weigh your rig with the coach fully loaded for a trip - water, black and grey tanks full (or just add the weight of about 8.5lbs/gallon for empty tanks).

Once you have your axle weights, look up your axle weight ratings to determine if you are overloaded on your axles. Nothing like a bent or broken axle to ruin a trip...

Your tire pressures for front vs rear tires are most likely going to be different.

If you want your tires to last longer, don't park them for storage directly on concrete. I use sheets of plywood on the concrete floor to separate the rubber from the concrete. I believe this is to prevent the concrete from drawing out the moisture in one spot of the tire (over long term parking) and causing premature tire failure. (This is straight from the Michelin website)...

Happy Travels,
Carl

[Slow Moon]

Originally Posted by FOURWHL

The correct answer is get your rig weighed and find the table for your tire manufacturer and fill to the pressure prescribed for that weight by the manufacturer of the tire. Any other methods are just less accurate guesses at achieving this. You can fill to max pressure to err on the safe side but your going to be making noticeable sacrifices in ride quality

ACTUALLY, to my knowledge, tire manufacturers do NOT prescribe any particular inflation pressure for any weight. I have seen manufacturer tables that provide MINIMUM inflation pressures for a given load. NOBODY here has been able to explain why anyone would want to use the MINIMUM allowable inflation pressure based on a table that is not specifically designed for their specific vehicle.

If anyone here thinks they can cite a table where any tire manufacturer does prescribe an actual inflation pressure that they are saying you should use, PLEASE PROVIDE A CITE to that table so everyone here can look at it and see if does indeed say what folks are saying it does. If any such table does indeed provide a prescribed inflation pressure, I'd be happy to stand corrected.

While it's almost always better to use max sidewall PSI for heavily loaded TRAILERS, there is a lot of room for debate on any given MOTOR VEHICLE that's not loaded to the max. In any case, I would not recommend using a minimum pressure specified on any table not specifically applicable to your vehicle.

[FOURWHL]

This sure looks prescribed to me: https://www.michelintruck.com/refere...tion-tables/#/

I’m not sure, but I’d think they’d put minimum on here somewhere if these were minimums. Those tables to me read as a load rating at a given pressure. Now do I recommend running at the pressure for the load exactly to what you weighed at? Well that’s kind of a judgement call as to how loaded you are. I personally run a few extra psi for good measure but well under max pressure.

Trailer tires? Absolutely run max sidewall pressures. But on a MH you’re asking for a crappy ride imo

[Webefine]

Originally Posted by fourwhl

this sure looks prescribed to me: https://www.michelintruck.com/refere...tion-tables/#/

i’m not sure, but i’d think they’d put minimum on here somewhere if these were minimums. Those tables to me read as a load rating at a given pressure. Now do i recommend running at the pressure for the load exactly to what you weighed at? Well that’s kind of a judgement call as to how loaded you are. I personally run a few extra psi for good measure but well under max pressure.

Trailer tires? Absolutely run max sidewall pressures. But on a mh you’re asking for a crappy ride imo

👍👍

[Coolbaldguy]

I agree with Fourwhl.

[Photo Lab]

Originally Posted by FOURWHL

The correct answer is get your rig weighed and find the table for your tire manufacturer and fill to the pressure prescribed for that weight by the manufacturer of the tire. Any other methods are just less accurate guesses at achieving this. You can fill to max pressure to err on the safe side but your going to be making noticeable sacrifices in ride quality

X2!
Every tire manufacturer has charts showing recommended tire pressure for each model and size of tire they make. As mentioned, get it weighed in full travel trim, and set the pressures according to the tire manufacturer's recommendations. Having too much air in tires isn't being on the safe side, but the opposite, as it reduces traction, as well as tire life.

[Slow Moon]

Originally Posted by FOURWHL

This sure looks prescribed to me: https://www.michelintruck.com/refere...tion-tables/#/

I’m not sure, but I’d think they’d put minimum on here somewhere if these were minimums. Those tables to me read as a load rating at a given pressure. Now do I recommend running at the pressure for the load exactly to what you weighed at? Well that’s kind of a judgement call as to how loaded you are. I personally run a few extra psi for good measure but well under max pressure.

Trailer tires? Absolutely run max sidewall pressures. But on a MH you’re asking for a crappy ride imo

1---They DO “put minimum on here somewhere” if you follow YOUR reasoning: You say, “Those tables to me read as a load rating at a given pressure.” Accordingly, the LT215/85R16 E shows on the charts to be rated at 3570LB @ 45 PSI and 3880 LB @ 50 PSI. It follows that 50 PSI is the MINIMUM inflation pressure allowed for 3880 LB, and you can clearly and prominently see that you should NOT run 45 PSI for a 3880 LB load. Moreover, you state that YOU actually run a higher pressure than the table shows, reinforcing the concept that YOU yourself consider the table pressures to be MINIMUMS.

2---Nowhere in Michelin’s chart do they say or imply you should not exceed the chart pressures. Don’t you think they would say so if they really thought that? They also do not say that it will decrease traction.

3---Nowhere in Michelin’s chart do they say or imply that you should actually use the table pressure for your particular application. They do NOT say they recommend, prescribe, endorse or approve using those pressures. Of course Michelin has no idea on what you are putting their tires.

4---It seems to me that EVERYONE here agrees that you should NEVER run any less pressure than shown on the charts, and you (and maybe all of us) agree that it’s OK to run more. If so, then we are all really in agreement that the charts show MINIMUM pressures. If you should not run less, and it’s OK to run more, is that not the definition of MINIMUM?

5---We ALL agree that you should NEVER run less than inflation table pressure, and it’s fine to run at least a bit more. Why not allow a 20% safety margin, and inflate to a pressure that provides a true 20% load capacity safety margin? Nowhere else do I see folks advocating zero safety margin. Why would we do that for our tires? Why would you deflate to the absolute minimum load rating?

6---If I THINK my motor vehicle tires see a 3000 LB load, I’m going to inflate them AT LEAST enough to carry 3600 LB. It WILL reduce sidewall flex and may stiffen the ride. That’s not a bad thing, as it will likely improve handling, especially if an emergency should arise. Unlikely you would be significantly less comfortable. We all would do well to recall the real world disaster that occurred when Ford Explorer drivers were told to reduce pressure to improve ride comfort. They were within load chart tables, but disaster was the result.

On my trailer, I inflate to 110 PSI for a 4400 LB load capacity and a 47% safety margin, but that’s a different matter.

Now if y’all motorhome guys want to run minimum pressures, I can’t stop you, so I avoid running near motorhomes. I have twice narrowly avoided collision when a nearby MH blew a front tire. Not a pretty sight in either case but both were lucky. Both went way off the highway, but neither overturned. Both were close calls for me.

Y’all run whatever PSI you want. I’ll steer clear.

[Slow Moon]

Originally Posted by Photo Lab

X2!
Every tire manufacturer has charts showing recommended tire pressure for each model and size of tire they make. As mentioned, get it weighed in full travel trim, and set the pressures according to the tire manufacturer's recommendations. Having too much air in tires isn't being on the safe side, but the opposite, as it reduces traction, as well as tire life.

Can you provide us a cite to a manufacturer chart that actually says "recommended tire pressure"? I've been looking and asking if anyone can provide that. If the charts do not actually say "recommended," they why would anyone post a comment that tells other people that they do?

I'd agree that "Having too much air in tires isn't being on the safe side," but I doubt you will be able to cite any manufacturer chart that says exceeding the chart numbers will result in "having too much air in tires." I have not seen any manufacturer chart say that higher pressures will reduce traction. That is not really the case, except possibly for very lightly loaded tires that you won't find on motor homes.

When posting about manufacturer charts, would it not be better to stick to what manufacturer charts actually say?

[FOURWHL]

Ok I’ll play your game. Show me in that page or any published document by Michelin that says those are minimum values not recommended. Shurely Michelin’s lawyers wouldn’t let them publish values They didn’t want people to use.

[BigRockr]

You knew it would go off the rails on page two.

[FOURWHL]

I guess there’s only so much to talk about with tire pressures. Got to fill the thread somehow...