Tire weight recommended tire pressure guides

[Crasher]

There is so much confusion on this subject that there should be a Sticky that covers it in depth. The load charts are designed by the tire manufacturers to provide a pressure that will provide the best traction, handling, and longevity of the tire. In other words, the safest psi for the load being carried. It's such a simple thing, but when some of the "Experts" on this forum say to go by the placard, or inflate to the psi on the sidewall, or some other figure because they squat better, it becomes very confusing to the new RVer.

This is one more reason to have an information class for first timers that would include proper tire care before they take possession. Even a Sticky written by a professional RV tire expert would answer this very simple, but misunderstood part of motorhome care. It would also eliminate some of the misinformation being repeated. I have used the load charts on our motorhomes and my personal trucks for decades and get the maximum tire wear without a single failure due to inflation. But, what do I know??

[Nasdaqsam]

Originally Posted by Crasher

There is so much confusion on this subject that there should be a Sticky that covers it in depth. The load charts are designed by the tire manufacturers to provide a pressure that will provide the best traction, handling, and longevity of the tire. In other words, the safest psi for the load being carried. It's such a simple thing, but when some of the "Experts" on this forum say to go by the placard, or inflate to the psi on the sidewall, or some other figure because they squat better, it becomes very confusing to the new RVer.

This is one more reason to have an information class for first timers that would include proper tire care before they take possession. Even a Sticky written by a professional RV tire expert would answer this very simple, but misunderstood part of motorhome care. It would also eliminate some of the misinformation being repeated. I have used the load charts on our motorhomes and my personal trucks for decades and get the maximum tire wear without a single failure due to inflation. But, what do I know??

Well put! Confusing is an understatement. So much information and mis-information as the case may be. I agree one comprehensive sticky would be a great resources for tires. Of the articles I have read most will at some point refer back to the manufacturer's placard which agrees to the lb with Yokohama's calculator. I am going to add 5lbs for my own piece of mind.

It's amazing though of all the shops I called around here they air them up to max cold PSI and call it a day.

Thanks for the input.

[Crasher]

In some cases, the placard is close, but in many it is much higher than needed. Mine said 100 psi on all tires. That would have left the front 5 psi below the minimum needed, the drive tires 20 psi higher than needed and the tag 25 psi too high. That left the front under inflated, and the rest overinflated for poorer traction when accelerating and braking. The load chart puts all tires at their safest operation, but I add 5 psi for POM.

[Gordon Dewald]

Originally Posted by Nasdaqsam

Well put! Confusing is an understatement. So much information and mis-information as the case may be. I agree one comprehensive sticky would be a great resources for tires. Of the articles I have read most will at some point refer back to the manufacturer's placard which agrees to the lb with Yokohama's calculator. I am going to add 5lbs for my own piece of mind.

It's amazing though of all the shops I called around here they air them up to max cold PSI and call it a day.

Thanks for the input.

The tire pressures on the charts and on the sticker and on the tire side wall are all MINIMUM pressures to carry the weight listed.

The tire sidewall lists the maximum weight the tire should carry when single.

The manufacturers sticker on the door pillar lists the minimum pressure for the GAWR of the coach. The GVWR should not be exceeded, nor the axle GAWR.

The charts by the tire manufacturers are for tires that are not loaded to the max.

Truck shops advise for the max pressure because the vehicles (OTR) they deal with are either loaded to the max or running empty. For an OTR driver to constantly change pressures is not practical. A gravel truck for example could be changing a dozed times a day. A long haul trucker could change daily to weekly. A MH on the other had generally is loaded to a fairly constant weight which does not change significantly.

Load you motorhome up with everything including water, fuel, passengers, etc. and weigh the axle. Corner weights are best. If not use the axle weight and a 5% split to estimate unbalanced loading. Using the increased weight inflate all the tires to the recommended minimum pressure for the axle. If you want to add more feel free.

[Crasher]

Originally Posted by Gordon Dewald

The tire pressures on the charts and on the sticker and on the tire side wall are all MINIMUM pressures to carry the weight listed.

The tire sidewall lists the maximum weight the tire should carry when single.

The manufacturers sticker on the door pillar lists the minimum pressure for the GAWR of the coach. The GVWR should not be exceeded, nor the axle GAWR.

The charts by the tire manufacturers are for tires that are not loaded to the max.

Truck shops advise for the max pressure because the vehicles (OTR) they deal with are either loaded to the max or running empty. For an OTR driver to constantly change pressures is not practical. A gravel truck for example could be changing a dozed times a day. A long haul trucker could change daily to weekly. A MH on the other had generally is loaded to a fairly constant weight which does not change significantly.

Load you motorhome up with everything including water, fuel, passengers, etc. and weigh the axle. Corner weights are best. If not use the axle weight and a 5% split to estimate unbalanced loading. Using the increased weight inflate all the tires to the recommended minimum pressure for the axle. If you want to add more feel free.

Gordon, How many times have you, myself and others given this same response to the famous "Tire Inflation" question?? And it keeps coming up over and over again. Each time all the different answers are given sometimes leaving the OP confused. Wouldn't it make sense to have a Sticky that provided the "Correct" RV tire inflation and care??

[hohenwald48]

Also, the pressure/weight rating for a given size and load range tire are the same regardless of the tire brand.

[jadatis]

Advantage of motorhomes and Travel-trailers is , that if you once weighed it , best per axle end, second best per axle, the weights wont chance that much in the years you use it. But you have to weigh fully loaded, as you go on trip.

Then you can add a reserve to the load of even 10% without gripp and comfort getting to bad.

then you can calculate the needed pressure with my made formula, wich is saver then the European official formula, wich on its turn is saver then the American official used fromula for LT and Truck-tires ( wich in fact your tires are).

As "pigheaded Dutch Selfdeclared Tirepressure-specialist" I can help you determining a save pressure with enaugh reserve and still acceptable gripp and comfort.

You can also use my made pressure/loadcapacity lists in next map on my public map of One-drive that belongs to my hotmail-adress with same username as in this forum.
https://onedrive.live.com/?id=A526E0EEE092E6DC%21904&cid=A526E0EEE092E6DC

Also there a spreadsheet to make your own list wich gives that there is not one ideal pressure, but a pressure range in wich your tires are save for the load and speed , up to maximum reserve without discomfort.

So what you suggest about a sticky , would only give different opinions about it, and ofcource mine is the best

[4x4van]

As hohenwald48 said, the weight/pressure range for a given size/load range of tire is normally the same regardless of tire manufacturer (or at least very close). And as jadatis said, even a sticky would likely just result in more arguments and debate. But is it really that complicated? As has been debated ad nauseum here and on other sites, there are really only 3 options.

Option #1: Run the pressure stamped on the tire sidewall. This is the wrong option. The tire manufacturer has no idea what rig you are putting that tire on, nor how you are going to load that rig. The sidewall information is simply the maximum weight that the tire should ever carry and the pressure required to support that weight. 90% of the time, if you run that pressure, you are over-inflated for your actual rig/load. Over-inflated tires result in a harsher ride, smaller contact patch, reduced braking and traction, compromised handling, and uneven tire wear.

Option #2: Run the pressures listed on the Placard mounted on your RV, which is based on your rig's GAWRs. This is usually a safe option, particularly from a manufacturer's liability standpoint, as those numbers are the pressures required for the maximum load that YOUR vehicle should ever weigh. The downside is that you MAY still be over-inflated (or even under-inflated), depending on your rig's actual weight.

Option #3: Weigh your rig, 4 corner, or at least front & rear, and set your pressures based on the tire manufacturer's load tables (they are the ones who know exactly what their tires will support and the pressure needed to support it). If your actual weight is close to the top of a specific step in those tables, bump your pressure up to the next step for an added safety margin. This is the best option, resulting in the best overall performance from your tires, including wear, handling, traction, control, ride comfort, safety...but requires some work on your part. It also requires you to occasionally (annually?) re-weigh your rig to account for "weight-creep".

Of course, I'm sure that some will disagree with at least part of that, so YMMV!

[cruzbill]

Everything you need to know about RV tires

RV Tire Safety

[Nasdaqsam]

I am going to get it weighed but for the upcoming trip it is not an option so going to have to go with manufacturer's recommendation and add a bit of safety.

What was extremely painful was going to the garage to watch a couple of the Good Years get taken off in absolutely mint shape inside and out. Not so much as a smallest of cracks or any sign off anything wrong. But that's water under the bridge the new ones are going on. The old ones had beads and wheel weights so not sure if those were so out of balance they required both or if the last installer was just lazy and did not remove the weights which would seem unusual. The one thing I will have in the way of knowing what the old would have done is the guy doing my change out is taking them and installing them on a low boy so we will see how many miles he gets out of them. Not the same as an RV but if they were going to blow he will find out. He tends to run to the max.

[Crasher]

Originally Posted by 4x4van

As hohenwald48 said, the weight/pressure range for a given size/load range of tire is normally the same regardless of tire manufacturer (or at least very close). And as jadatis said, even a sticky would likely just result in more arguments and debate. But is it really that complicated? As has been debated ad nauseum here and on other sites, there are really only 3 options.

Option #1: Run the pressure stamped on the tire sidewall. This is the wrong option. The tire manufacturer has no idea what rig you are putting that tire on, nor how you are going to load that rig. The sidewall information is simply the maximum weight that the tire should ever carry and the pressure required to support that weight. 90% of the time, if you run that pressure, you are over-inflated for your actual rig/load. Over-inflated tires result in a harsher ride, smaller contact patch, reduced braking and traction, compromised handling, and uneven tire wear.

Option #2: Run the pressures listed on the Placard mounted on your RV, which is based on your rig's GAWRs. This is usually a safe option, particularly from a manufacturer's liability standpoint, as those numbers are the pressures required for the maximum load that YOUR vehicle should ever weigh. The downside is that you MAY still be over-inflated (or even under-inflated), depending on your rig's actual weight.

Option #3: Weigh your rig, 4 corner, or at least front & rear, and set your pressures based on the tire manufacturer's load tables (they are the ones who know exactly what their tires will support and the pressure needed to support it). If your actual weight is close to the top of a specific step in those tables, bump your pressure up to the next step for an added safety margin. This is the best option, resulting in the best overall performance from your tires, including wear, handling, traction, control, ride comfort, safety...but requires some work on your part. It also requires you to occasionally (annually?) re-weigh your rig to account for "weight-creep".

Of course, I'm sure that some will disagree with at least part of that, so YMMV!

My suggestion for a sticky would be one written by an Tire Expert like Roger Marble aka: Tireman9 on this forum. With the many years of his experience and access to proven data, who could argue with his statement of fact?? Some may well think their way is better, but until they have the years of data to substantiate their claim, Tireman9's guideline would remain the only proven method. In fact, why allow any comments on the sticky that would only add confusion to a very simple process?? Some may choose to ignore guidance from a tire expert, but most would appreciate the correct method for arriving at the correct tire pressure.

[Gordon Dewald]

Originally Posted by Crasher

Gordon, How many times have you, myself and others given this same response to the famous "Tire Inflation" question?? And it keeps coming up over and over again. Each time all the different answers are given sometimes leaving the OP confused. Wouldn't it make sense to have a Sticky that provided the "Correct" RV tire inflation and care??

Absolutely. Even then someone will come up with what they think is a brilliant exclusion to physical rules. At times I believe they make outrageous statements just to elicit a response. Hopefully they are not that ill informed.

[Nasdaqsam]

Ok, so the Yoko's are on, we did the beads as no one around here has a spin balancer for this size tire. The installer aired them up to 120 all around before I had a chance to tell him what I wanted. No big deal I will let some air out when I get home.

before I start the next statements I want to say right now the coach is all but empty just some tools, 3/4 tank of water and empty grey and black so as light as this coach is going to get. And these tires are rated WAY over anything this coach was rated for.

What a difference between the Yoko's and the GY's. I never would have thought it was possible to gain this much better a ride which was impressive but the control and handling is night and day. This thing feels like a sports car. All be it a 32000lb sports car......lol

Once home I went to 90 rears and 110 fronts. And took it for another ride.
I don't like this at all they feel just like the GY's. Not that they were bad just not very responsive. The closest reference I can think of would be comparing a 1980 Caddie to a new BMW. Lower pressure and they give a good ride but feel soft and not as responsive. I definitely like the higher pressure ride and control and really no significant lose of ride that I could feel. Now this is on dry roads so I know going to the higher pressure I will be giving up traction and foot print but the control is significantly better.

Thoughts?

[Mudfrog]

Originally Posted by Nasdaqsam

Ok, so the Yoko's are on, we did the beads as no one around here has a spin balancer for this size tire. The installer aired them up to 120 all around before I had a chance to tell him what I wanted. No big deal I will let some air out when I get home.

before I start the next statements I want to say right now the coach is all but empty just some tools, 3/4 tank of water and empty grey and black so as light as this coach is going to get. And these tires are rated WAY over anything this coach was rated for.

What a difference between the Yoko's and the GY's. I never would have thought it was possible to gain this much better a ride which was impressive but the control and handling is night and day. This thing feels like a sports car. All be it a 32000lb sports car......lol

Once home I went to 90 rears and 110 fronts. And took it for another ride.
I don't like this at all they feel just like the GY's. Not that they were bad just not very responsive. The closest reference I can think of would be comparing a 1980 Caddie to a new BMW. Lower pressure and they give a good ride but feel soft and not as responsive. I definitely like the higher pressure ride and control and really no significant lose of ride that I could feel. Now this is on dry roads so I know going to the higher pressure I will be giving up traction and foot print but the control is significantly better.

Thoughts?

On our relatively light coach with 19.5s, running maximum pressure gives a harsh ride. Going with what the placard states, 75 psi front and rear, the ride is good. Those pressures put the tire capacity just a tad bit over the GVWR. Since we've had this rig, i've always used the 10% rule (then rounded up to the next 5 psi increment). Running at 85 psi provides a firm but good ride and that's worked fine for the 14 years we've had the rig.

On yours, if it handles better and is not too rough a ride at the higher pressure, then go for it. I don't think you'll be losing much, if any, footprint or traction.