RW 427 Tire Pressures?

[Tapps33]

Hey Guys! I’m new to the forum, and have only owned my 426 since July. However, and pretty much anything that could go wrong has, I’ve been trying to check as many systems as I can prior to making any more long trips. One thing I can’t seem to find specs on is the tire pressure. Right now, it appears as though the forward 2 axles are set at 80psi, and the rear (or third axle) is set at 90psi.

If if anyone knows where to find these numbers, I would be greatly appreciative!

 

[jimtoo]

Hi Tapps33,

Welcome to the Heartland Owners Forum and to the family. If you have any questions we have a great bunch of folks here with lots of information and all willing to share their knowledge when needed.

Your tires will have max pressure rating in the side of the tire along with weight capacity. Inflate tires to max pressure listed on tire.

Be sure and join our Heartland Owners Club. Then join us at a rally when you can meet lots of the great folks here and make friends for a lifetime.

Enjoy the forum.
Jim M

 

[jleavitt11]

I would look at the specs printed on the tires. You should have Sailuns on your RW and I would guess you should be running 110 PSI. That is where I run our Cyclone.

 

[Tapps33]

Yes, I do have the Sailuns on there. I actually downloaded the loading vs inflation pressure guide from Sailuns site. I just wasn’t sure if running 110psi when not fully loaded would cause the tires to bulge along the centerline?


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[RickL]

The best method is to know exactly what your individual tire position weighs. Then using the load and inflation chart set ALL tires to the tire that carry’s the most weight. You don’t need to add 5 lbs or inflate to the max (unless according to your chart that is where it needs to be set).

As as you can see you will get a number of “tribal” knowledge answers. I was in the tire industry for 35+ years dealing with any tire out there, passenger, light truck, over the road, off road and mining, and as such feel the information provided is the only sure way to set pressures. One could make the case to inflate to the maximum psi listed, but in many instances it is way overkill that will promote irregular wear patterns on the tire.

 

[Tapps33]

Thanks for the input! I had a feeling that was the best way to go. Now I just need to find some scales!

Anyone have any ideas who might have them?


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[WBG]

Thanks for the input! I had a feeling that was the best way to go. Now I just need to find some scales!

Anyone have any ideas who might have them?


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Just do a search on truck scales near you. I found one at the place where I get dirt/mulch/gravel for the yard. (They mostly deal with Landscape contractors. Easy to deal with and usually not at all busy.

 

[Lynn1130]

As as you can see you will get a number of “tribal” knowledge answers

Interestingly, Discount Tire, that handles thousands of tires monthly, inflate to the rating on the label on the inside of the door of the vehicle (off door side of your trailer). If you are using recommended specs for tires for your vehicle the pressure on the side of the tire is almost always the same as your vehicle sticker. In the case of your trailer, unless there is something really different about it, the pressure will be the same for all four tires. The axles are meant to distributed the weight equally, therefore the same pressure.

 

[Tapps33]

To be honest, I’ve checked every door on the camper looking for the specs and couldn’t find them. I’ve even looked through the literature that came with the camper. I was kinda hoping someone else with a 427 would have the stickers on their unit.

I’m wondering if it’s because this is a toy hauler and the weight distribution can dramatically change, they don’t put “specs” on here, just manufacturer’s recommended inflation tables.


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[danemayer]

To be honest, I’ve checked every door on the camper looking for the specs and couldn’t find them. I’ve even looked through the literature that came with the camper. I was kinda hoping someone else with a 427 would have the stickers on their unit.

I’m wondering if it’s because this is a toy hauler and the weight distribution can dramatically change, they don’t put “specs” on here, just manufacturer’s recommended inflation tables.


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Look up front on the off-door-side. There's a metal plaque that shows the GVRW and max load for fully inflated tires.

Assuming your tires match that plaque, the sidewall of the tire will show the same inflation to provide max load capacity.

Most of our RVs, when loaded for travel, are close to the GVWR. Given that, inflating the tires to the pressure shown on the sidewalls is a good idea. If you've weighed the trailer and are significantly below GVWR, you might want to reduce pressure slightly. But keep in mind that if your inflation is below 80% of what's necessary, some manufacturers call that a "run flat" tire that may have permanent damage.

Also keep in mind that weight is often not evenly distributed. If you reduce pressure, one tire could be underinflated.

In most cases the best thing to do is inflate the tires to the cold max pressure setting as shown on the sidewalls.

 

[Lynn1130]

My plaque is about eye height (5'9") on the off door side (driver's) about 4 feet back from the front of the trailer.

 

[Tapps33]

Thanks for the input, I’ll see if I can find it!




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[Tapps33]

You guys were right! I found the data plate, it was hidden on my model though, they put it right in front of my face!

110 psi across all 3 axles, looks like I’ve got some inflating to do!


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[tireman9]

You might want to review the topic of Interply Shear on TT application. I cover this in my RV Tire Safety blog.

Basically you should run the inflation on the side of the tires associated with the max load. You shoulsalso ensure the measured scale weight is no more than 90% (85% max is better) than the tire max load capacity. AND keep your speed to 65 or less as thaat is the speed used to calculate the tire load capacity for ST type tires.

 

[jleavitt11]

Help me understand. If we should inflate the tires to the rating listed on the tire why don't we use the speed rating listed on the tire. They are either both right or both wrong.

Just my opinion.

 

[Tapps33]

Thanks for all the good input! I’m going to inflate my tires to the 110 psi max rating for the Sailuns. After doing a lot of research, the tires are actually rated at 75 mph, which was a pleasant surprise! (Usually they’re bad surprises).

As for measuring the individual weights, finding scales is the tricky part. When I was working on airplanes, finding scales for weight and balance was extremely difficult....unless you had $15K for a set of your own...which I don’t.

Thankfully though, I’ve got the triple axle toy hauler set up, and I never actually haul anything. The garage is the baby’s room, not a garage. Hopefully, between the three axles they won’t be overloaded individually.


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[tireman9]

Help me understand. If we should inflate the tires to the rating listed on the tire why don't we use the speed rating listed on the tire. They are either both right or both wrong.

Just my opinion.

Load capacity is a fundamental part of physics. Air pressure and volume (tire size) support the load. The formula for ST tires is based on an assumption of 65 mph max. There is no magic in the letters "ST" and if you look at the load capacity of LT tires (higher speed) what was the trade-off that would give ST tires more capacity?

ST tires started to carry Speed Symbol in 2017 to avoid import duty.

The Speed Symbol is from an SAE tire test that specifically says it is for Passenger type tires. IMO the speed letter placed on tires is primarily for marketing.
The SAE test is actually a "heat resistance " test and only requires a tire be capable of running 30 minutes at the speed when the tire is loaded to 88% of max sidewall load.

Can you run faster than 65? Sure. You can also end up with 3 year tire life or belt separation that may cost you $thousands. Your choice