# 4.80x12 tire pressure??



## Blake

For hauling a relatively light load like a 1542 with a 25 hp outbound and gear, what tire pressure should I use for highway use? The max is 60, and I've always run the max on my bass boat trailers, but 60 sounds like a bunch with a light load. Also, what is the max speed I can pull those tires?


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## TNtroller

I would start out at 45 psi and see what the tires do COLD, do they squat/bulge/look low for the load and adjust from there. Then take it for a 10-20 mile test and see what the tires look like, how much of the tread is actually on the pavement at operation temps. Does the trailer when loaded bounce on every expansion crack/bump/etc., in the road, and adjust as needed. If you always have a light load in the boat (gas/gear/etc) do the test run this way or heavily loaded if that's the way you fish. Every rig is a bit different due to the equipment each person hauls around.


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## lckstckn2smknbrls

Put the tires at 60 and leave them there. If the trailer is to bouncy either add weight to the trailer or remove a leaf from the spring pack.


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## BigTerp

I always inflate my trailer tires (boat, camper, box) to the maximum tire pressure listed on the sidewall. Trailer tires are meant to be run at the maximum pressure. Under inflation WILL cause you problems eventually.


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## Johnny

the tires on my one ton Dodge 15 passenger van is for 85psi on the sidewall.
The manufacture's tag on the inside of the door call for 65 front and 55 back.
85 on all four tires will send you into a white knuckle ride like you have never experienced.

There is - and always will be - a war between the tire companies and the
automobile companies over which is right. In the meantime, innocent
people are being killed in crashes strictly related to improper tire inflation and care.
Either under or over inflation will cause tread separation . . . . educate yourself.

your call


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## DaleH

_Here's what I used to do ... _at least until I looked into it for myself after BigTerps's post below ...

I'll initially put them to 75% to 80% of the sidewall tire pressure (based on an informal calculation of what my rig weighs and the apparent 'loading' on the tires) and then take the rig out for a 5-10 mile spin and then swing by the house and douse the ties well wet with the hose. Then I will move down the 'dry' road a bit, pull over and examine the 'footprint' left by the water marks. 

You can easily see if the center of the tire is leaving a bigger or more noticeable footprint than the sidewalls, which would indicate excess pressure for the load carried. You can also just as easily see if the sidewalls of the tires are leaving a bigger footprint than the center, which would indicate too low of a pressure setting _for that load/rig as towed_. 

*Edit* - See post below ... BigTerp is quite correct that the trailer tire makers recommend running them at the max rating.


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## KMixson

The max pressure on the sidewall states the maximum pressure for the maximum load. If you are not going to be hauling anywhere near the maximum stated load I would back off the pressure a little. You then need to keep a close eye on the tire temps to make sure you are not under-inflating them. If you under inflate them the tire will flex more causing heat which will cause tire failure. An under-inflated tire increases rolling resistance which also causes the bearings to work harder. You will then need to keep a closer eye on the bearings also. There is a happy medium but finding it is tricky.


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## BigTerp

Again, *TRAILER* tires are meant to be run at the maximum rated pressure. The OP is not referring to passenger vehicle tires. Please don't confuse passenger tires with ST tires. Trailer tires have a stiffer sidewall and are meant to be run at the maximum pressure. The stiffer sidewall not only accommodates higher pressures but helps prevent trailer sway. If you run ST tires under inflated they will heat up more and eventually fail prematurely. 

Passenger tires are a different ball game. I run higher pressure, close to the max, in my '07 F-150 if I am hauling a load of stone or something else really heavy, but other than that I run them at around the recommended PSI.


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## DaleH

BigTerp said:


> Again, *TRAILER* tires are meant to be run at the maximum rated pressure. The OP is not referring to passenger vehicle tires. Please don't confuse passenger tires with [trailer] ST tires.


Well, I'll freely *admit to it that BigTerp was indeed right! *See: https://m.discounttire.com/dtcs/infoTrailerTireFacts.do , linked from Carlisle Tires.

While what I had been doing always worked for me, after his last post I looked up a few known trailer tire makers ... and son of a gun they indeed recommend you run at the max pressure. BigTerp was right ... and I was wrong  , but learned something ...

Now I'll edit my post above ... LOL 8)


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## HeavyHook

BigTerp said:


> Again, *TRAILER* tires are meant to be run at the maximum rated pressure. The OP is not referring to passenger vehicle tires. Please don't confuse passenger tires with ST tires. Trailer tires have a stiffer sidewall and are meant to be run at the maximum pressure. The stiffer sidewall not only accommodates higher pressures but helps prevent trailer sway. If you run ST tires under inflated they will heat up more and eventually fail prematurely.
> 
> Passenger tires are a different ball game. I run higher pressure, close to the max, in my '07 F-150 if I am hauling a load of stone or something else really heavy, but other than that I run them at around the recommended PSI.



After doing a lot of research on the subject I can confirm trailer tires are manufactured differently and are meant to be run at maximum pressure.


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## fishmonger

Just picked up a new EZ Loader with 4.80 x 12s. The 81 year old gentleman that owns the trailer sales went over the trailer checked the lights and air in the tires. He looked at the tires and said, "Yep, they get 60 lbs". I thought that was a lot and he said to me, "Son (had to laugh because I'm 67) I've been doing this a hell of a long time and when it says 60 lbs on the tire that's what you put in".


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## HeavyHook

fishmonger said:


> Just picked up a new EZ Loader with 4.80 x 12s. The 81 year old gentleman that owns the trailer sales went over the trailer checked the lights and air in the tires. He looked at the tires and said, "Yep, they get 60 lbs". I thought that was a lot and he said to me, "Son (had to laugh because I'm 67) I've been doing this a hell of a long time and when it says 60 lbs on the tire that's what you put in".



haha that is great. The first time I went to put air in the tires I saw the amount needed, second guessed that amount, asked my father who had towed many boats in his time and then second guessed his answer. I researched like a mad man online and even called a few boat stores etc until it seemed everyone but a random 1-2 said to always inflate trailer tires to the specified amount. 

I then thought they all must be crazy and even contacted the manufacturer who let me know how they are built just like online had told me and to always fill them up to the specified amount. 

I apologized to my father the next time we went fishing and filled those tires to the specified amount and have not had any problems.


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## lovedr79

i was thinking 60. as i didnt like the idea of putting that much in.


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## Defiant

I have a EZ-Loader with 4.80x12s on it bought it new in 08-09 has Carlisle Sport Trail tires they have been run at 32 PSI since new and gonna need replaced soon the treads are getting pretty worn on them never have had a problem even running interstate speeds


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## lckstckn2smknbrls

Defiant said:


> I have a EZ-Loader with 4.80x12s on it bought it new in 08-09 has Carlisle Sport Trail tires they have been run at 32 PSI since new and gonna need replaced soon the treads are getting pretty worn on them never have had a problem even running interstate speeds


Different load rating on the same size tire require different PSI.
Match the load rating on the tire to the load on the trailer and run the max air pressure.


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## Defiant

Trailer is rated at 1200 lbs Tires are load range B Carlisle Sport Trail 2ply Max Pressure is 60 PSI . Ive had them at 32 for 8 Years never a problem


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## momule

Defiant said:


> Trailer is rated at 1200 lbs Tires are load range B Carlisle Sport Trail 2ply Max Pressure is 60 PSI . Ive had them at 32 for 8 Years never a problem



Obvious where you got your nick  . My only comment is that you must happily be the exception to the rule. I agree with the majority after doing a lot of looking and asking: my tires are run at the recommended pressure always and I have never had a problem. I also change my tires every 3rd year because even if those inexpensive tires sit all the time 8 years is enough time for dry rot to set in and the rubber to change.


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