What Class A Tire Pressure 2022 Adventurer 29B

[martybhawk]

I have 2022 Adventurer 29B with Goodyear G670 Tires 24570R19.5G. Sticker shows GVWR - 18,000 GAWR Front - 7,000 Rear - 12,000 Cold Inflate to 82 psi
Weighed fully loaded w/full tank gas, no water in holding at Cat Scale - Front Axle - 6,060 Rear - 11,520 Total 17,730

1. What PSI should I use for front and rear?

2. Am I too close to GVWR?

Thx

[wahoonc]

You need to be running max sticker pressures. You aren't over your GVW on either axle which is a good thing. What is your CCC? Right now you are about maxed out with no wiggle room.

Aaron

[tim myers]

Everyone needs to make their own choices, but I am not in the max pressure camp for my tires. However, given how close to gross weight you are that may be the correct answer for you.



I see that you weighed with no water in the fresh water tank. Is that how you normally travel, with no water? My fresh water tank is usually full when I am on the road and was full when I weighed my Journey on a Cat Scale.

FMCA recommends four corner weights but unless you are at one of their rallies it is difficult to get four corner weights. I use my front and rear axle weights and multiply by .6 for my corner weights which I hope accounts for any imbalance left to right. I then use the manufacturers tire chart to determine the tire pressures I use.



As an example my 265/75R22.5 have a max pressure of 120#. Based on the actual weights I am running I run 100# on the steer axle and 85# on the drive axle. Winnebago has recommended tire pressure settings for my Journey as 110 front and 95 rear. These pressures are based on the Michelin tires that were on the rig when new and also based on being at gross weight. These are still lower then the max pressure raring of my tires.






Advantages of less pressure are 1. Smoother ride 2. Less chance of uneven wear 3. Better traction 4. Less chance of an over pressure alarm on your TPMS, assuming you are running one.

[Wyatt]

I have a placard with the same TP recommendations

I’m also maxed out on CCC, so I use the placard numbers @ 82 PSI on all six tires, then add 10% for a buffer since I can’t weigh all for corners.

That was recommended personally from a forensic tire expert…

https://www.rvtiresafety.net/search/label/Inflation

[Ray,IN]

Originally Posted by tim myers

Everyone needs to make their own choices, but I am not in the max pressure camp for my tires. However, given how close to gross weight you are that may be the correct answer for you.



I see that you weighed with no water in the fresh water tank. Is that how you normally travel, with no water? My fresh water tank is usually full when I am on the road and was full when I weighed my Journey on a Cat Scale.

FMCA recommends four corner weights but unless you are at one of their rallies it is difficult to get four corner weights. I use my front and rear axle weights and multiply by .6 for my corner weights which I hope accounts for any imbalance left to right. I then use the manufacturers tire chart to determine the tire pressures I use.


As an example my 265/75R22.5 have a max pressure of 120#. Based on the actual weights I am running I run 100# on the steer axle and 85# on the drive axle. Winnebago has recommended tire pressure settings for my Journey as 110 front and 95 rear. These pressures are based on the Michelin tires that were on the rig when new and also based on being at gross weight. These are still lower then the max pressure raring of my tires.






Advantages of less pressure are 1. Smoother ride 2. Less chance of uneven wear 3. Better traction 4. Less chance of an over pressure alarm on your TPMS, assuming you are running one.

The vast majority of tire failures result from overloading/underinflation. A car tire is inflated to pressures with a 35% safety margin, RV tires normally lave less than 10%.. Using load/inflation charts means the tires are operating at 100% capacity continually, well until a cold morning drops pressures below chart levels.

[Tireman9]

Originally Posted by martybhawk

I have 2022 Adventurer 29B with Goodyear G670 Tires 24570R19.5G. Sticker shows GVWR - 18,000 GAWR Front - 7,000 Rear - 12,000 Cold Inflate to 82 psi
Weighed fully loaded w/full tank gas, no water in holding at Cat Scale - Front Axle - 6,060 Rear - 11,520 Total 17,730

1. What PSI should I use for front and rear?

2. Am I too close to GVWR?

Thx

GVWR is just a number. The tires on the front axle have no "idea" how much load is on the tires on the rear axle.


The number on your Certification label is GAWR for each axle. Your actual truck scale reading should be no more than 90% of GAWR. You can use the truck scale weight for each axle and the Load Inflation tables to learn the MINIMUM tire inflation pressure, after adjusting for the 10% margin recommended by RVIA B U T this means you are assuming you are in the 1% to 2% of RVs that have a perfect 50/50% load split end to end for each axle.




I do not understand why so many people want tocut the safety margin with their tires so cloas to the limit. I have read where some calculate a 10% loss in tire strength per year of use.

[ACB]

Originally Posted by martybhawk

I have 2022 Adventurer 29B with Goodyear G670 Tires 24570R19.5G. Sticker shows GVWR - 18,000 GAWR Front - 7,000 Rear - 12,000 Cold Inflate to 82 psi
Weighed fully loaded w/full tank gas, no water in holding at Cat Scale - Front Axle - 6,060 Rear - 11,520 Total 17,730

1. What PSI should I use for front and rear?

2. Am I too close to GVWR?

Thx

There are a lot of opinions given on this string . Some may be correct, some , maybe not, and some maybe subjective. I live in Arizona , with extreme heat and excessive road heat. .

I have a 2022 Vista29V, basically the same rig as you.
18,000 GVW with 2042 CCC. 19.5” tires.
We weight our rig regularly, have traveled 36,000 miles on these tires and regularly weigh at Cat scale between 17,500 to 17,800 pounds.
It is very difficult to get below 17,000 with our rigs. We are only two people, don’t fill the fresh water but 25 gallons and literally weight everything that goes into the coach. We don’t fill bins because “we can”.

I’ve been to the big Ford truck repair shop in town, been to Winnebago twice, been to a high end heavy truck tire shop here in Phoenix that is extremely knowledgeable.
Per their instructions to me: DO NOT MAX OUT your cold tire pressure.
Our rigs have the same axles, brakes, and tires as the 22,000 Lb GVW rigs.The leaf springs are the limiting factor on our rigs.The tires can handle much more weight, but don’t run the tires max on our rig.

My rigs sticker says 82psi cold. My tire expert recommended 75psi for smoother ride and handling. And that was after he weighed my rig.I run my tires at 78 psi cold, a small compromise to his recommendation . I have driven over 200,000 miles on motorhomes over the years but I ALWAYS take the advice of the truck tire experts,


My option : don’t take my word for it or trust the RV dealer. Find a good heavy truck tire shop. I think you will get solid information. FREE.
I hope this helps

[GotUr6]

Some good advice from other replies. All I would highly recommend is to get your rig weighed with the weight you normally drive. The go from there.

[Bobn1957]

The placard in the coach lists the tire pressure for the original tires the coach came with, if you have different tires than the original ones go to the tire manufacturer and look up your weights for the correct pressure!

[Dr. Hoopty]

As an owner of a rig similar to yours and the same size tires, I run 95 psi cold all the way around. I usually do carry a full water load depending on where I'm going. This gives me enough headroom to allow me to fully load up and not worry about my tires. I have a commercial driver license and I’m a heavy Equipment mechanic so I’m used to how trucks handle and drive. I personally think that running your tires below 90 is not particularly safe, especially when you’re fully loaded. This is something that people always comment about and like what was said previously, under inflated tires are a huge problem when it comes to failure. I really don’t think that dropping your tire pressure makes much of a difference in the ride. It will always be a medium duty truck with a beam front axle!

[ACB]

I appreciate your concern. I too am a former commercial truck driver , who drove construction rigs and heavy machinery working my way through college and my engineering degree. . Not sure how heavy your rig is, which could make a difference. As I mentioned, I’ve reviewed my 18K F53 rig with Ford and reviewed tire loading/pressure charts for my Goodyear tires with reputable tire shops after reviewing tire manufacturers loading charts. I feel good how I’m running them. I feel the research is solid.

But I sincerely appreciate your input and concern. Thank you.

[Tireman9]

I understand how this mis-information occurs. People decide to read the wording on the side of their tires and not the Federally mandated vehicle Certification label.


As I have said numerous times before, "Max Press" on the tire side wall IS NOT the highest pressure an undamaged tire can tolerate. It is simply the highest pressure that will give you the highest load capacity. Increasing the pressure above that number WILL NOT give you any additional load capacity. Since we all know, or should know, that it is the air pressure that supports the load and not the tire. Some think that they will get more load capacity by increasing the PSI but that is not the case once you get to the "Max PSI" number on the tire sidewall.


As far as tire loading and inflation goes, the MAX number, is a hard stop, as is the GAWR for each axle. You can make modifications to the RV such as springs or air bags or even tire size and Load Range but those changes WILL NOT increase the GAWR.


GVWR IS NOT the same as GAWR. It is the number for the heaviest the vehicle total can weigh. There are a number of RVs out there where the GVWR is lower that the mathematical total of the GAWRs. You should NEVER exceed either the GVWR or any of the individual GAWR numbers.


RE Cold inflation. This is the number found in the Load & Inflation tables and is the MINIMUM PSI you should ever run for a tire with a measured load. Running any lower pressure will "consume" the tire life and can result in tire failure. Damage to the tire structure is CUMULATIVE. Once you do some damage, no matter how minor, that damage will never go away and will never repair itself.
Damage occurs as you drive and can even occur when parked. Just because you are currently driving at 54 mph and at a load below the maximum shown in the tables does not mean that you can not have a failure as the tire might have been damaged by the pothole you hit 249 miles earlier.

[ACB]

Excellent points.

[David_Laura]

I'm in the midst of buying new steer tires for my rig. Most manufacturers have Load vs. Pressure tables available, some even on-line. My name plate said 85 psi but the tire manufacturer recommended about 70 psi (cold) for my load.

It may explain why the original tires wore out along the center rib.

I'm open to your tire reviews for 245/70R-19.5

[ACB]

Originally Posted by David_Laura

I'm in the midst of buying new steer tires for my rig. Most manufacturers have Load vs. Pressure tables available, some even on-line. My name plate said 85 psi but the tire manufacturer recommended about 70 psi (cold) for my load.

It may explain why the original tires wore out along the center rib.

I'm open to your tire reviews for 245/70R-19.5

I replaced the original Goodyear front tires due to unusual wear at 20,000 miles . Here in Phoenix I found a heavy duty truck tire shop that specializes in heavy trucks and Motorhomes. Per their recommendations (and also that of the Ford truck dealer) I stayed away from Continental tires due to short lifespans.
They said the Goodyears that came with the rig were very long lasting but also hard riding.
The tire shop recommended the Sumotomo brand. Instead, but he also mentioned Kelly tires. Not as long lasting as the Goodyear but I opted for the Kelly tire. At 16,000 miles on the Kelly’s, they look great, handle well and appear to ride a little softer. I run them at about 78psi cold.
On my class C rigs I always ran Michelin tires for softer ride.

Hopefully my experience helps.

[Tireman9]

Originally Posted by Bobn1957

The placard in the coach lists the tire pressure for the original tires the coach came with, if you have different tires than the original ones go to the tire manufacturer and look up your weights for the correct pressure!

Unless you changes tire size and/or Load range the load capacity is almost always the same. Just changing brand does not automatically mean the load capacity is different.


The Certification label PSI is what is required to support the GAWR for Motorhomes.

[Tireman9]

Originally Posted by David_Laura

I'm in the midst of buying new steer tires for my rig. Most manufacturers have Load vs. Pressure tables available, some even on-line. My name plate said 85 psi but the tire manufacturer recommended about 70 psi (cold) for my load.

It may explain why the original tires wore out along the center rib.

I'm open to your tire reviews for 245/70R-19.5

The "Certification Label" lists the GAWR, tire Size and Load Range and inflation required to support the GAWR.

If that shows 85 psi and your new tires show 70 you may have selected the wrong tire size or Load Range and are overloading the tires.
What is the Cert. label show for GAWR and tire size and L.R.?
What size and Load Range tire is on the RV now?
What is the actual load of Front and Rear axle?


This info is important as we are talking potential tire failure and safety here.

[Ray,IN]

Originally Posted by ACB

There are a lot of opinions given on this string . Some may be correct, some , maybe not, and some maybe subjective. I live in Arizona , with extreme heat and excessive road heat. .

I have a 2022 Vista29V, basically the same rig as you.
18,000 GVW with 2042 CCC. 19.5” tires.
We weight our rig regularly, have traveled 36,000 miles on these tires and regularly weigh at Cat scale between 17,500 to 17,800 pounds.
It is very difficult to get below 17,000 with our rigs. We are only two people, don’t fill the fresh water but 25 gallons and literally weight everything that goes into the coach. We don’t fill bins because “we can”.

I’ve been to the big Ford truck repair shop in town, been to Winnebago twice, been to a high end heavy truck tire shop here in Phoenix that is extremely knowledgeable.
Per their instructions to me: DO NOT MAX OUT your cold tire pressure.
Our rigs have the same axles, brakes, and tires as the 22,000 Lb GVW rigs.The leaf springs are the limiting factor on our rigs.The tires can handle much more weight, but don’t run the tires max on our rig.

My rigs sticker says 82psi cold. My tire expert recommended 75psi for smoother ride and handling. And that was after he weighed my rig.I run my tires at 78 psi cold, a small compromise to his recommendation . I have driven over 200,000 miles on motorhomes over the years but I ALWAYS take the advice of the truck tire experts,


My option : don’t take my word for it or trust the RV dealer. Find a good heavy truck tire shop. I think you will get solid information. FREE.
I hope this helps

And don't trust your tire guy. Heed what Tireman9 says, he is a retired tire construction engineer and an expert in tire forensics(determining the cause of a tire failure)
re; your 200,000 miles of driving a MH. Have you ever worn off the tread to the minimum olf 6/64 for steer tires? If not Contenental tires will serve you well.

[Wyatt]

Spot on…