Load Range G - Montana Owners Club

MAMalody · 04-16-2009, 07:23 PM

When I went to NE last year I lost a tire in Baker, OR. Replace two load range E tires with two load range G tires, the only ones they had. I aired them to 80# and had no problems for the 4000 mile trip. Getting ready to head to KY from WA and am wondering if that pressure is safe. Some say they should be aired to 110# not 80#. I have been told that my 2003 OEM rims won't take 110#. Is there a problem if I run them at 80#? Will they act like they are underinflated and run hot?

Second, each time I have take off cross country I lose a tire. Between the damage and the tire cost it is a real pain. I do check my tires every day before I head out. I am wondering about getting pressure pro or similar system to help me keep up with the tire pressure. Does that sound like a good investment?

ols1932 · 04-17-2009, 01:57 AM

Is it a good investment? Those of us who own the system will say a resounding YES! It sounds like it may have been helpful for you had you had the system. As for running the G-rated tires at 80 psi, not being a tire expert, but having had a lot of experience with RV tires, I would say this probably won't hurt. It depends on how much load you have on the rig. The 110 psi is for full load so I'm sure you can run them at lower pressure if you're not fully loaded.

Lonnie B will be along and will clarify for you.

I was told that my rims wouldn't take the 110 psi rated tires (Load range G), and if yours are the same, then you have to be careful.

Additionally, if you have these two tires on your rig, they should be on the same axle.
Orv

LonnieB · 04-17-2009, 03:33 AM

Orv is right, you can run the G rated tires lower than 110 psi as long as you aren't overloading them. 110 psi in the G rated tire will carry a maximum load (weight) of 3750 pounds, at 80 psi the maximum load (weight) is reduced to around 3042 pounds. The chart below should help.

PSI.....MAX LOAD
85......3170
90......3300
95......3415
100.....3550
105.....3675
110.....3750

The only way to determine the correct psi, is to weigh the trailer at the axles while hooked to the TV, with the trailer fully loaded.

You will probably have to remove one of the wheels and look on the back side to find the max load and psi for the wheel. If the max psi is less than you need, you have two options.

1. Buy new wheels with the proper rating.
2. Go back to the E rated tires.

stiles watson · 04-17-2009, 08:06 AM

I totally agree about the Pressure Pro system. You will be able to monitor all your wheels, RV and TV.

I run my G-rated tires between 100 and 105. The Big Sky might be a bit heavier. The only way to really know is to weigh your rig and pressurize accordingly.

virgil47 · 04-17-2009, 04:21 PM

Please pay attention to what Lonnie said about your wheels/rims. Stamped on the backside of the rim is the MAX pressure you should run on that rim. Even if your tire is good to 110psi., if your rims are 80psi max, then you should only run 80 or else the rim can crack. I speak from experience. On my Montana I had 60psi rims on a 3555RL which called for E rated 80psi tires. I bought it secondhand so could never prove that it came from the factory that way.

MAMalody · 04-17-2009, 06:24 PM

I seem to remember the inside of the rim said 3042. I think that is what I saw when they were installed. I explained the above information (I thought I read that here before) to the tire guy where I bought the tires and we did not seem to be on the same wave length. I called my son who used to manage a Discount Tire Store and he said go ahead an get them and just not inflate above 80#s...which I have not. By the chart, it looks like I am ok?

skypilot · 04-21-2009, 06:56 AM

Mike: That 3042 you saw is the maximum weight that the rim is designed to carry as well. Given that, and looking at LonnieB's post above, I'd be inclined to think you have 80 PSI rated rims as well. If your trailer weighs more than this on each wheel, you do need to look into it.

Now, that said, there were some earlier posts and pictures where the rim distributer had upped the weight / PSI ratings for Montana. You may need to call them and find out if your rims are now certified for higher and get the necessary paperwork from them...

Best wishes on getting this resolved.

helmick · 04-21-2009, 07:17 AM

On my 2007 3400 inside the rim it said 100# rated.

MAMalody · 04-21-2009, 06:04 PM

Quote:

quote:Originally posted by skypilot

Mike: That 3042 you saw is the maximum weight that the rim is designed to carry as well. Given that, and looking at LonnieB's post above, I'd be inclined to think you have 80 PSI rated rims as well. If your trailer weighs more than this on each wheel, you do need to look into it.

Now, that said, there were some earlier posts and pictures where the rim distributer had upped the weight / PSI ratings for Montana. You may need to call them and find out if your rims are now certified for higher and get the necessary paperwork from them...

Best wishes on getting this resolved.

My GVW is 14000#, the tires would be 12000# does that mean I am overweight per my tires or is that adjusted by the hitch weight?

skypilot · 04-23-2009, 05:22 AM

It is adjusted for hitch weight -- is supposed to be just what is carried by the tires. On my SOB, it originally came with wheels marked as yours. I upgraded the axles to Lippert 7K and disc brakes and when I did I also had to purchase new wheels because the 'allowable' weight on the axles exceeded what the wheels could carry (Lippert sales/installation tech told me all of this the day I arrived to have the work done at their place in Goshen). MY GVW didn't change - still 13,800.

exav8tr · 04-23-2009, 12:10 PM

Mike, if your GVW is 14000, you need to deduct the pin weight to get the weight on your axles. or, another way of doing it is just roll your trailer wheels on a scale and weigh, make sure they are pretty far forward on the scales and truck wheels are off.

RKassl · 04-26-2009, 02:57 AM

For the wife and I the tires on the trailer and the tv are everything. We upgraded to Goodyears G16's a couple of years ago, and with the advice from MOC spend the $$ for the Pressure Pro TPMS..This is by far the BEST upgrade to the Montana that I have ever done. Gives great piece of mind.

exav8tr · 04-26-2009, 03:38 AM

Quote:

quote:Originally posted by RKassl

For the wife and I the tires on the trailer and the tv are everything. We upgraded to Goodyears G16's a couple of years ago, and with the advice from MOC spend the $$ for the Pressure Pro TPMS..This is by far the BEST upgrade to the Montana that I have ever done. Gives great piece of mind.

Bob, Did you upgrade your wheels also or do you just go to 80 psi in your tires?? I'm trying to get a handle on this pressure thing....

RKassl · 04-26-2009, 03:58 AM

Great question. The OEM rims on my Montana were only rated for 80lbs. To go to the Goodyear G16's you must have a high pressure wheels. My tire man found some rated at 110lbs and also put in high pressure metal valve stems. These tires are great they are designed for unique stresses from trailer towing. I found lots of info at the Goodyear web site.

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