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crabbey1 · 12-24-2013, 08:07 PM

I am looking for some help with setting my tire pressure correctly. I have done research but it is very confusing stuff IMHO.

Here is my setup:

2005 Ford F150 Lariat 5.4L
Tires: Michelin LTX M/S2 P265/60R18
Max PSI: 44

I read that I should have the rear tires inflated to MAX psi to help with the load and sway. Not sure about the front.

1976 Argosy 22'
Tires: Goodyear Marathon ST225/75R15
Max PSI: 65

Trailer Hitch Weight: 560 lbs.

I looked at the load chart and I settled currently on 50 psi which should give me a 2150(C) rating x 4 tires = 8600 lbs.

My trailer weighs about 3360 dry. It will never be over 5800 lbs. (GVWR). I figured that is a good margin for error. Any thoughts?

I think that is all the info needed. If any other info is required, please let me know. Thanks for any and all help!!!

switz · 12-24-2013, 08:12 PM

The GYM need to be at 65psi because of their construction.

Switching to Michelin LTX (P) 235/75R15 XL tires @ 44psi on the 15" factory wheels is a better ride for the trailer and more tire patch contact than the GMY tires for better braking. See the picture under in my "images" below my avatar of a GYM beside the Michelin mounted on the same factory wheels. There is no 65mph speed limit printed on the sidewall of the Michelin as there is on the GYM tires.

There was a 24% load margin with the Michelins when I loaded the 2013 25FB International Serenity to 6,960 pounds camping ready.

**DKB_SATX** · 12-24-2013, 08:23 PM

Running the truck's rears at max PSI when towing will do no harm. I run my F150's rears at 42 PSI (with Cooper Discoverer XL tires in the same size) and it's stable, the tires run a few degrees hotter than the fronts, which is to be expected since they're the drive wheels but no problems in 10k miles towing the 24' Argosy.

I initially had Carlisle Radial Trail LRC tires on the Argosy and ran them at 50 PSI (max for the Cs) and now I'm running the 15" Michelin XLTs at 50 PSI (their sidewall max) with excellent results so far.

bwoodtx · 12-24-2013, 09:13 PM

On the trailer I run the tires at the manufacturer's suggested maximum inflation rating. On the truck, I run the rears at maximum inflation and the fronts are 5-10psi below maximum. If the fronts are at maximum then the steering becomes too "quick".

crabbey1 · 12-24-2013, 09:46 PM

This all sounds great. I will upgrade the trailers tires when the old ones have used up their life. They still have another 20k in them probably...

I think max all around except the front tires on the tv sounds good.

CapriRacer · 12-25-2013, 05:58 AM

Quote:

Originally Posted by crabbey1

I am looking for some help with setting my tire pressure correctly. I have done research but it is very confusing stuff IMHO.

Here is my setup:

2005 Ford F150 Lariat 5.4L
Tires: Michelin LTX M/S2 P265/60R18
Max PSI: 44

I read that I should have the rear tires inflated to MAX psi to help with the load and sway. Not sure about the front.

1976 Argosy 22'
Tires: Goodyear Marathon ST225/75R15
Max PSI: 65

Trailer Hitch Weight: 560 lbs.

I looked at the load chart and I settled currently on 50 psi which should give me a 2150(C) rating x 4 tires = 8600 lbs.

My trailer weighs about 3360 dry. It will never be over 5800 lbs. (GVWR). I figured that is a good margin for error. Any thoughts?

I think that is all the info needed. If any other info is required, please let me know. Thanks for any and all help!!!

You left off an important tidbit of information.

What pressure does your tow vehicle tire placard say? The placard is on the driver's door frame.

Also, the tire size is there. That is also important.

I looked up your truck in Tire Guides - a book that summarizes vehicle tiere placards - and they say the vehicle tire placard will say 35 psi. Check that.

Now what is on the vehicle tire placard is supposed to cover ALL situations delineated there - and if they don't make any distinction,, the pressure specified includes max loading of the truck.

So I think the proper pressure for the tow vehicle is 35 psi. I can see running a few psi more just for insurance, but I think 9 psi more is too much.

switz · 12-25-2013, 08:52 AM

Be sure to check the date code on the tires of both the truck and trailer. Mileage is not the only criteria and perhaps not as important as time since heat and UV from the sun dry out the oils in a tire. The consensus is changing at four but no later than five years after the date code on the sidewall of the tire.

The date code is four digits in the format WWYY where WW = week and YY is the year.

Wazbro · 12-25-2013, 12:32 PM

Quote:

Originally Posted by crabbey1

This all sounds great. I will upgrade the trailers tires when the old ones have used up their life. They still have another 20k in them probably...

I think max all around except the front tires on the tv sounds good.

99% of noncommercial trailer tires should be changed out on age long before they should be changed out on tread ware.

On my truck the manufacturer recommends a MINIMUM pressure of 32 psi the tire max is 44 psi and I normally run 40 psi in all TV tires while towing. My truck does have a starting weight distribution of about 48% front 52% back though which is a lot more front-end weight then most trucks.

crabbey1 · 12-25-2013, 03:27 PM

Well, I ran into my problem. The trailer tires are all old. They were manufactured 49th week of 2005. So they are about 8 years old. I guess I need new tires. I cannot spend over $600 MAX but would love to stay lower if possible... What should I replace thsee bad boys with...

Also, I checked the spare for the trailer, it was manufactured 2nd week of 1993. I would say it has seen better days. I never really checked cause it was wrapped in a plastic bag.

crabbey1 · 12-25-2013, 04:32 PM

I found these for $101 each. Not bad...

http://www.tirerack.com/tires/tires....ARV2&tab=Sizes

crabbey1 · 12-25-2013, 04:43 PM

SWITZ: Are these the tires you are referring to?

Michelin LTX M/S2 Tire P235/75R15/XL 108T - Walmart.com

**DKB_SATX** · 12-25-2013, 04:48 PM

The tires you linked from Wal*Mart are in fact the ones that many of us run on our trailers that have a low enough per-tire weight, with excellent results.

The C-rated Marathons you linked from TireRack should do fine and save you some money in the short run at least. You may have to actually buy them from TireRack to get the LRCs, around here tire places carry mostly LREs with a few LRDs in stock, but the Cs will have plenty of load-carrying capacity for your 22'.

crabbey1 · 12-25-2013, 04:58 PM

I also found these locally but they were manufactured in 2009.

ST225/75R15 Carlisle Radial Trailer Tire LR C 2,150 lb Capacity 2009 Date Code Stored Indoors

What do you guys think of a tire that has been stored since manufacture date?

**DKB_SATX** · 12-25-2013, 05:12 PM

If they are almost free and you plan to replace them in about a year that should be okay. I would not go for them otherwise.

Those are barely even discounted.

crabbey1 · 12-25-2013, 05:21 PM

Yeah that is what I was thinking... I was wondering if I could bargain with them...

I did find an America's Tire location 20 miles from me that has 4 GYM's in stock...

Shopping Cart Expired - America's Tire

Should I just tow the trailer over there or take the wheel 2 at a time? I only have 4 jack stands. Can I leave the trailer sitting on just 4 stands?

crabbey1 · 12-25-2013, 05:24 PM

Also, does anyone have any experience with America's Tires Certificates for Tire Protection? This is what their site says:

In the event one or more of your tires with certificates fail due to defect, or incurs road hazard damage that cannot be repaired, America's Tire will replace it at no additional charge. Regardless of the number of miles you put on the tires, you will be covered for the life of the original tread down to 3/32" remaining, or 3 years from the date of purchase, whichever occurs first. We have offered certificates for over 30 years; they are unbeatable in the tire industry!

Sounds good but am I not covered under the manufacturers warranty? At $15 per tire does this seem worth it?

bwoodtx · 12-25-2013, 05:29 PM

You can support that trailer on 4 jackstands just fine. Two at the tongue and two behind the wheels. Do NOT jack on the axle.. only the frame.

You have a nice, rare trailer. I would not skimp on tires. The Michelins are what I run on all my trailers. Especially the one I transport my dogs in.

Wazbro · 12-25-2013, 05:33 PM

Quote:

Originally Posted by crabbey1

I also found these locally but they were manufactured in 2009.

ST225/75R15 Carlisle Radial Trailer Tire LR C 2,150 lb Capacity 2009 Date Code Stored Indoors

What do you guys think of a tire that has been stored since manufacture date?

I would not trust tires that have been sitting in storage that long, nearly 5 years old already.

You could try these, they have the same capacity as the 15" Michelin tires people have been using, much cheaper though.
http://www.tirerack.com/tires/tires....XLV2&tab=Specs

My brother has a set of Kumho tires on his truck that have been good, haven't tried them on a trailer though.

crabbey1 · 12-25-2013, 07:46 PM

OK. I think I am going with the GYM's because I found a local place that has a great price and I can pick them up in their warehouse. I hope they are open in the AM. Next I need to find a place to mount and balance the tires... It never ends.

MARATHON RADIAL - OnlineTires.com

crabbey1 · 12-26-2013, 10:21 AM

OK, I am heading out in a few to get some new tires. I had one last thought in my head before I stepped out the door. Is there a difference in the lifespan of the GYM vs. the Michelins? Meaning can the Michelin safely be in service past the 5 year date or do any tires need replaced at that time period? I would gladly pay the extra cost if that was the case....