50 psi tire pressure?

Just watched "Video 33, Hi-Lo Inspection" in the library. It states tire pressure should be 50 psi. When I talked with someone from JR Enterprises they said 32 psi. Who is right?

seseeley said:

Just watched "Video 33, Hi-Lo Inspection" in the library. It states tire pressure should be 50 psi. When I talked with someone from JR Enterprises they said 32 psi. Who is right?

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My Hi-Lo, with OEM Load Range C tires, was placarded to require 50 psi. If your tires are rated that high for their cold inflation pressure, that's what I'd use. But, if you don't have "trailer tires" installed, you need to respect the max pressure value shown on the sidewalls.

- Jack

JackandJanet said:

My Hi-Lo, with OEM Load Range C tires, was placarded to require 50 psi. If your tires are rated that high for their cold inflation pressure, that's what I'd use. But, if you don't have "trailer tires" installed, you need to respect the max pressure value shown on the sidewalls.

- Jack

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I agree with Jack on that. I don't know where the JR boys came up with 32 psi.

I looked back at my notes ... the JR boys stated 32psi for 13" and 55psi for 15". My 1995 23' FunLite has the 13" tire size. I'll look at the sidewalls tonight.

My 95 originally had 4 ply 13 inch tires, PSI was 32, I put 6 ply rated 13 inch tires on it and they were 50PSI.

This post "morphed" into a discussion on trailer tires:

http://www.hilotrailerforum.com/f19/tow-vehicle-tire-inflation-2213/

My 2001 had 32 psi on the 13" tires, also. Also- it was on the "card" on sideof trailer. I have upgraded tires with 50 psi rating and was advised by my dealer to go 50.

Rick

Check the tire sidewalls this weekend and they are a C load tire stating 50psi. Can't find any specification anywhere on the trailer. Where might I find markings on the trailer?

seseeley said:

Check the tire sidewalls this weekend and they are a C load tire stating 50psi. Can't find any specification anywhere on the trailer. Where might I find markings on the trailer?

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That is usually on a sticker that could be located on the outside driver side on the upper section. They may not have always put them on trailers years ago. If there is no sticker, go with the tire marking. Whomever made the tires should know.

And, to add to this - when you inflate trailer tires to the sidewall pressure, they are able to carry their "rated load" which should also be on the sidewall. If you inflate to anything less, the safe load they can carry is reduced. Ideally, the trailer weight should be no more than 80% of the load carrying capability of the tires.

Inflating to the max value reduces tire flex that causes heat buildup, which on a trailer tire rapidly reduces its useful life.

- Jack

whatever the sidewall specifies on your tire,thats what it should be inflated to. just make sure that you do not have a mixmatch of "car" tires and trailer tires,they handle differently and could affect brake stopping

This is a lengthy post but I feel it may be helpful to many who have questions about how much air pressure one should run in our HiLos.

As Hilltool said in an earlier post; this post site has "morphed into a trailer tire discussion" from its original post. I probably am the cause of that ‘morphing’ as I brought this up when the discussion forum was actually about the TV tire pressure. The morphing came about because after experiencing a blow-out on our HiLo that was sitting in our driveway, and had sat idle in our driveway for over three months, I discovered my 6-year old HiLo had original tires on it that were 9 years old. In my search to find and purchase replacement tires, I ran across several discussion groups and experts attesting on how to determine the proper tire pressure for your RV.

Since that time there have been several postings from raamw and me on what we have learned and the reasons for using tire pressures other than what is arbitrarily embossed on each tire [which is the maximum tire pressure rating for that tire]. There are many tire manufacturers that may recommend the same tire that spans several different RV weights. The difference in recommended tire pressure comes about due to the differences in the weights of the RVs. For example, if a manufacturer recommends the same tire for a variety of trailers weighing from 5500 to 8600 pounds loaded weight, that indicates to me that the air pressure requirements would be different for me if I am at the lower range of the trailer weight scale versus another who might be at the upper end of that scale.

Our HiLo dry weight is, 4525 pounds with my estimated loaded rate at approximately 5500 pounds. This same tire that I selected could safely be used on a trailer weighing 8600 pounds. The heavier trailer would require the maximum tire pressure of 65 pounds while our HiLo would require as little as 35 pounds on the same tire.

All that raamw and I have tried to bring to the forefront is that if you have a lighter RV and you air the tires up to the pressure that is embossed on the tire, [always the recommended maximum cold pressure], you may impact the performance of that tire when travelling down the interstate. The 'footprint' is all-important, per the experts, and when you take one of our lighter HiLo's and place maximum tire pressure as embossed on the tire, you reduce the footprint and may affect the stopping power or curbing ability of your HiLo. This may become more of a safety issue when travelling on rain, snow, or ice.

Case in point; I recently purchased a new set of tires for our HiLo. I opted for 8-ply tires for extra safety and performance and the occasional higher speed when necessary. The 6-ply tires I had just taken off had a maximum tire pressure rating of 50 pounds. The maximum pressure listed for the tire I chose is 65 pounds. What has changed except the tire? The HiLo trailer is the same and the only variance would be the load we put on the HiLo.

In an earlier post by seseely, it was brought out that a HiLo information film stated the tire pressure on their HiLo should be 50 pounds but when J&R Repair was questioned about it, they said it should be 32 pounds. I'm suggesting that J&R quoted the air pressure for that particular tire and that particular HiLo Trailer's weight based on what various experts have determined.

Following is a graph taken from a Goodyear site that has this statement in the information leading up to the link. I call your attention to a paragraph preceding the load/inflation table [shown below].

http://www.goodyearrvtires.com/pdfs/tire-care-guide.pdf

What you should know about tire load and inflation.
The recommended maximum inflation pressures for your tires are indicated on the certification label or in your
owner’s manual. Because RVs can be loaded with many different configurations, the load on each tire will vary.
For this reason, actual air pressure required should be determined based on the actual load on each individual tire.
Inflation pressure should be adjusted to handle the tire carrying the heaviest load, and all tires on the axle should
be adjusted to this pressure.Each manufacturer provides load and inflation tables specific to its products to help you
determine the correct tireInflation pressure for your vehicle’s loading.

Here is a portion of the table that applies to our HiLo and the particular tire I chose for it:

Cold
Air Pressure
In Pounds 35 40 45 50 55 60 65 70 75 80
Weight 1390 1530 1660 1820(C) 1910 2030 2150(D) *[I could not get the columns to align; refer to the link to see the graph]

The above scale is for the tires I purchased ST235/75R15 Load Range D 8 Ply [Maximum cold air pressure 65#]
2406 T Unloaded Vehicle Rating UVR = 4525 pounds
MY estimated Loading weight = 1000 pounds
Adjusted Loaded Vehicle Rate ALVR = 5525 pounds
Weight per dual axle [4 tires] [1382 pounds each tire]
Safe Air Pressure/Tire 35 pounds

According to the Goodyear table above, when considering my tire rating, and my estimated loaded rate, my tires could be safely inflated to as low as 35 pounds. To compensate for any misjudgment I might make and to compensate for extra weight Carol may sneak into the cabinets for extra pots, pans, groceries, bath, bedding, etc., I have decided to air the tires somewhere between 40 and 45 pounds, well below the maximum of 65 pounds that many would put in the tires. If I carried the maximum pressure indicated on the tire, my HiLo could handle a payload of 2150 pounds, well over the actual 1000 or so pounds we will load on the HiLo.

To end this post [finally] here is a posting by a ‘Tire Geek’, a self-identified know-it-all expert on tires and tire pressures, which he very well may be. I happen to agree with him.

How do I determine the correct air pressure for my tires? - Yahoo! Answers

While this may not be popular with many HiLo owners who will insist on airing to the maximum rating of their tires regardless of what many experts and studies might recommend, I am going with it. If I find I am incorrect in these recommendations, I will let the forum know at a later date.

Jerry Curtis
2406T

The only sticker I found on the trailer was a warning about checking tire pressure before traveling. But no tire pressure information found anywhere else. I'm only the second owner. The original owner didn't remove stickers of any kind.

I've been running at 32 psi but the trailer seems kind of bouncy. I'm going to give 50 psi a try and see if it helps with the bounce factor. If 50 psi doesn't help I'll end up adjusting psi to load weight.

If your tires have a maximum psi go with that. Running the tires with too low of pressure invites trouble. What year and model is your HiLo?

just changed my signature.

1995 23' FunLite running:
Goodyear Marathon ST175/80R13 load C (max load 1360 lbs at 50 psi)
4 ply (2 poly 2 steel) 2 ply sidewalls

Trailer Data

I'll try to load, if I remember how, two pictures of our trailer decals regarding tire pressure. The decal says 50 PSI and that's what I've used since day one. Tires were mfg in 2006, are in good condition, but I will be replacing them in the spring before our next trip. As with trailer weight issues, tire pressure is another matter that is all over the place, often with too many experts. What was always preached to me (e.g. Consumer Reports, et al) was to follow the door post and trailer decals for tire pressure. Anything less or more would affect handling and tire condition. My TV pressure is 29 psi but the dealer always jacks it up higher. Have no idea why.

Just got back from this weekends camping trip. Ran the trailer with tires inflated to 50 psi. What a difference 50 psi makes as compared to 32 psi. The bounciness was hardly noticeable. I believe 32 psi is under inflated.

I think inflation by weight (Goodyear procedure) will be about 40 psi. I wonder if "trailer ride" with tires inflated to 40 psi is closer to 50 psi or 32 psi? I need to find a place to weigh the trailer and give it a try.

I noticed that the tires on my F150 have a maximum pressure of 44 psi, but there is a note on them to use the pressure specified by the vehicle manufacturer. In my case that is 35 psi. I have never seen that note on tires before.

OK, so after reading this entire thread there seems to be some disagreement and I'm confused on what pressures I should be running on both my TV and the trailer. When I picked the trailer, my Tahoe tires were at the max pressure (44 psi) indicated on the sidewall. Normal pressure is 32 according to the doorjamb sticker. The seller of the trailer thought I should have around 80 psi in the Tahoe tires!

The trailer tires I bought have a D load rating with a max of 65 psi. I noticed later that the tire store had put in around 45. What gives?

Luckydog671 said:

OK, so after reading this entire thread there seems to be some disagreement and I'm confused on what pressures I should be running on both my TV and the trailer. When I picked the trailer, my Tahoe tires were at the max pressure (44 psi) indicated on the sidewall. Normal pressure is 32 according to the doorjamb sticker. The seller of the trailer thought I should have around 80 psi in the Tahoe tires!

The trailer tires I bought have a D load rating with a max of 65 psi. I noticed later that the tire store had put in around 45. What gives?

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Truck tires I run @35psi (max 44). Trailer D rated tires always run at 65psi

I pretty much agree with Les. To get the max load carrying capacity on the D-rated trailer tires, they should be inflated to 65psi. If you inflate them to 50 psi, their load capacity is equivalent to C-rated tires (a bit over 1800#). They also run hotter, due to constant tire flex, which reduces their useful life faster.

Where I don't quite agree is the pressure on the tow vehicle tires. I suggest that you inflate them to the pressure shown on the door sticker if you are NOT towing. That pressure is supposed to give you the best combination of ride comfort and tire wear. But, when towing, there is more weight on the tires, which flexes the sidewalls more and spreads out the footprint. In this case, I would increase the cold inflation pressure, but don't exceed the maximum shown on the sidewall. In your case, I think I'd try 40 psi. Your goal is to reduce the sidewall flex to "normal", which reduces the running temperature in the tires. Reducing the footprint back to normal will also reduce edge wear on the tread.

I've got D-rated Maxxis tires on my trailer and they are ALWAYS inflated to 65 psi. I recently mounted E-rated LT Michelins on my truck and their max pressure rating is 80 psi. I am staying with the door sticker pressure (40 psi - what Michelin recommends) when not towing, but when I tow, I'll try 50-55 psi for starters. I have tire pressure/temperature sensors on all the tires, so I'll see how that works out. I used to increase the pressure on the old truck tires to their max, 44 psi, when I was towing, but I could tell it was not enough.

- Jack