80 PSI on Aluminum Wheels

Thanks for all the information and entertainment. After reading your posts and doing a little research I realized I asked an unfair question. Without knowing more about my rims there would be no way to know their pressure rating.

The answer was find the load rating on the rear of the rim. With this information and the provided pressure vs load chart I can determine their pressure rating.

But it's dark when I get home from work. I don't feel like moving the FW onto the pavement, drag out the jack, break loose the lugs, jack it up and remove the tire in the middle of the night!

While sitting on my comfy couch watching the Astros win the WS I researched rims. I concluded the rim size, # of lugs and pattern would define their load rating. I have 15" 6 lug 5.5" pattern. With this new information I started searching rims.

Within five minutes I found THESE. Hey, that's my rim. With laptop and flashlight in hand I go out to the FW to compare my rims to this photo. Exact Match. I have no doubt these are my rims and I have no doubt I will find 2830 stamped on the back side of my rims. This web site states they are rated to 80 psi.

With this information I will have the GY Endurance with high pressure stems installed and aired to 75 psi this weekend. If I see the need to increase them to 80 psi I will do so without concern. Heck, these tires will be so overrated I may run them for eight years without worrying about them. I keep them covered when not in use.

Now the next question is do I balance them? I started a new thread HERE.

Thanks guys :C

Goodyear also says this;

Goodyear Tire and Rubber .... weighing RVs
Special Considerations

*Unless trying to resolve poor ride quality problems with an RV trailer, it is recommended that trailer tires be inflated to the pressure indicated on the sidewall of the tire. Trailer tires experience significant lateral (side-to-side) loads due to vehicle sway from uneven roads or passing vehicles. Using the inflation pressure engraved on the sidewall will provide optimum load carrying capacity and minimize heat build-up.*

I've also had contact with Goodyear 1-800 and Goodyear truck tire dealer when I had several trailers on the road. All said to use max pressures in their tires on any multi-axle trailer. Trucks and single axle trailers they recommended the minimum pressure charts (psi for the load).
rvtiresafety.com
fiftwheelstreet.com
rvsafety.com
Tireman9
have all recommend max sidewall pressures for tires on a mult-axle trailer.
Truck tires with the wheel at the corners don't operate in the same environment ( sliding sideways while making turns.....weight changes in strong side winds/etc).


Now if the trailer owner has over tired the trailer such as using a 4080-4400 lb load G tire on 5.2/6k axle with 2500-2800 lb load per tire then I like this advise from rvsafety.com
Tire Load and Inflation Ratings

Note: Towable – Travel Trailer/ 5th Wheel owners Due to the severe use conditions experienced by tires when axles are very close together – tire industry experts recommend maximum (sidewall) inflation pressure for towable tires unless this causes a sever over-inflation situation (20 psi+), often referred to as the ‘basketball effect’. If this is your situation allow a 10 – 15psi safety margin above the minimum required inflation pressure.

Never heard of derating a tire on a multi-axle trailer till I became a member of a rv forum.

Cummins12V98 wrote:

ford truck guy wrote:
Right off the GY site -

"Correct tire inflation is a key component in tire care. The recommended maximum inflation pressures for your tires are indicated on the certification label or in your owner's manual. Since 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 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 standard."

Goodyear RV Tire Link

Of course it says that but please state what they say when up sizing load range???????

Not arguing, I just posted the link is all... The folks who run at max no matter what can research that if they want..I know my individual wheel weights and had aired my tires accordingly

Cummins12V98 wrote:

SoundGuy wrote:

Cummins12V98 wrote:
"According to Endurance owners the tire is stamped on the sidewall "inflate to xx psi"."

I bought a set this summer for my tandem axle boat trailer. I weighed the trailer and run 55psi instead of the 65 on sidewall. I will have to investigate further but I am fairly certain it says "MAX inflation 65psi".

In fact what is imprinted on the sidewall of a Goodyear Endurance tire is - "FOR MAX LOAD INFLATE TO XX PSI". In the case of my ST205/75 R14 Endurance that XX would be 65 p.s.i. which is how I run mine on wheels which previously wore off shore shoes in a C load range rated for 50 p.s.i. Some new Endurance owners seem to want to run less than full rated pressure but I wouldn't be one of them - mine run great at their maximum rated 65 p.s.i.

Please explain WHY you run full psi when your load may only require 55psi?

I do it for the additional margin or extra capacity. The tire is only as strong as the air it contains. I want the full load carrying capacity of the tire even if I don't need it.
When my rig is banging into potholes on I-81 I want the trir to be as sturdy as possible.
I have had to blow outs caused by potholes. However moving to a heavier maximum inflated tire has resolved my issues inflated.
I'm less concerned about wear and longevity than I am about a total failure due to impact. I want zero flex.

SoundGuy wrote:
...contrary to opinion from those who've never owned a set it doesn't tow harshly at all when inflated to their maximum rated pressure...

4x4van wrote:
Aside from the fact that your Federal Tire Placard calls for 50psi, I'm not sure how you could possibly make the statement that it "doesn't tow harshly at all" unless you are actually riding in the trailer while traveling down the road...:just sayin. :D

The tire placard affixed to the trailer says 50 p.s.i. because it was originally equipped with LR C tires, now it has LR D rated for 65 p.s.i. and no doubt the placard would have indicated that pressure had the trailer originally been equipped with these LR D Endurance tires. And why would I care about the ride inside the trailer when I'm never there? ... what I do care about is how much more smoothly it tows wearing these new LR D Endurance tires inflated to the maximum 65 p.s.i. - no pitching, no heaving as it used to do with the original set of soft sidewall, off shore tires, now it just tracks smoothly behind the truck. Can't ask for better than that. :B

A note, there is no "Max Pressure" for a truck tire. If you read the sidewall, it gives a max load at a pressure. Most state you can go well above that pressure, but rims become the limiting factor.

so, I guess I'm way overinflating my truck tires and GM doesn't know how to read a chart.

10,000GVWR, 7200lbs unloaded
rear inflation at max load 75psi=3100lbs x2 =6200lbs
front inflation at max load 60 psi=2760 x 2= 5520 lbs

total is 11,720, 1720lbs OVER Max GVW. almost 20 percent over GVWR

even when unloaded the recomended pressures of 60psi both axles exceeds the 10,000GVWR by a considerable margin, and is way over the empty weight of 7200lbs. almost an extra 4000lbs.

if I go strictly by inflation charts I'd be around 45 front, 35 rear unloaded.
quite a bit below the recomended inflation.

and even with this inflation "overload" my tires have always worn evenly.

doing the same calculation on both my cars yield similar results. recomended inflation pressure are well above max GVW of the vehicle.

Now, would I run 80psi on a TT tire only needing 40? no, but I wouldn't run 40psi either, probably 60 or 65 psi.

ford truck guy wrote:
Right off the GY site -

"Correct tire inflation is a key component in tire care. The recommended maximum inflation pressures for your tires are indicated on the certification label or in your owner's manual. Since 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 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 standard."

Goodyear RV Tire Link

Of course it says that but please state what they say when up sizing load range???????

"1) higher inflation will give more load carrying margin"
2) higher inflation will reduce heat buildup
3) higher inflation will help for lateral load stability

Overinflation causes tire wear, poor ride and longer stopping distance. Ask GY Tech support they will tell you to run tries 5 psi over what the load/inflation chart says when going up in load rating.

As I have said before I ran 85psi on GY "G"'s per GY's advise when upping my load range from "E" to "G". I would run 80 with the "E" tires because the load dictated 80.

But hey blindly use the sidewalls MAX # if U want when up sizing load range if U want but that is NOT what the experts say that make the tires.

SoundGuy wrote:

...contrary to opinion from those who've never owned a set it doesn't tow harshly at all when inflated to their maximum rated pressure...

Aside from the fact that your Federal Tire Placard calls for 50psi, I'm not sure how you could possibly make the statement that it "doesn't tow harshly at all" unless you are actually riding in the trailer while traveling down the road...:just sayin. :D