I'm having a heck of a time trying to find the correct tire pressure for my horse trailer tires. It is a "Cato Custom" 6 horse aluminum slant load gooseneck with a small dressing room and two axles (4 tires).  It is about 10-15 yrs old. I tried contacting Cato Customs, but they appear to have gone under. I asked Nelson's in Ocala and the guy said they always max out their tires to the PSI stamped on the sidewall - 80 PSI. That sounds high to me since the tires on my dually show 80 PSI max, but Ford says to run 50 in the front and 65 in the rear. Currently, we run 70 PSI, but have had two blowouts of good tires in the last year.

Any input would be appreciated.

Tom

That big of a trailer, assuming it has load range E tires then I would run the maximum pressure that's stamped on the tire( example: 235-85R-16 lrE, inflate to 80 psi) If your tires are older than 5 years old, then I suggest that you replace them, they may not be worn out but they have been exposed to 5 years of "the elements," (Florida sun)  and are deteriorating. Soon to blow out when you least expect it!!

Cato Classic Horse Trailers, over at Hernando, Fl. closed it's doors a couple years ago.

To get the highest load factor and the coolest running on a loaded tire, use the numbers found on each tire's sidewall. Each manufacturer will rate his tire based on his testing and experiences. The same sized tire made by different manufacturers will result in different load ratings.

The inflation numbers stamped on a truck's data plate, is an average figure that will result in an acceptable ride and loading factor. The Explorer/Firestone debacle is an example where ride was considered over the load, and the tires were run underinflated with the resulting accidents. This number will not result in the highest load factor a truck will handle.

If you are constantly having blow outs, you should consider trying to figure out a pattern. Some questions would include: Are the failures always on the same side of the trailer or random? Do they fail when the trailer is loaded or empty or both? Are your tire pressures constantly monitored? What speed were you traveling when they failed?

Have you replaced the damaged tires with the same brand? When they failed, did you have a dealer try to determine a cause?

I would first try to determine where on the trailer they were located. If it's in the same spot, there can be several reasons; axle alignment, loading, brake problems even a wheel bearing or the trailer's attitude when loaded. If it's one side, the passenger or driver's, it may be a driving problem dropping the tires off the edge of the road etc. If it is completely random, I would suspect the tires and consider changing brands.

There are many good brands of tires and a few bad ones. A search through these postings will give you many ideas about which are most favoured and which are scorned.

BOL  Gard

Tire size/load/inflation ratings are set by the "industry", not the manfacturers. The ratings should be the same for a given tire size no matter the manufacturer. The inflation numbers on the data plate are what is necessary to meet the axle ratings.....generally have nothing to do with ride. IF you are under the axle rating then you COULD run less psi.  I sure dont run the 80psi in the rear of my truck empty, ruins the center of the tire not to mention lack of traction.  Some 3/4 ton+ trucks have loaded/empty ratings, but they are few and far between. I dont remember seeing an actual conclusion to the Explorer/Firestone thing, mostly just finger pointing............

What size tires?  What does it weigh?  How fast do you drive? If youre haveing blowouts at 70, 80 probably wont make much difference. 

What happens to a soft tire on the front of a truck when you go around a corner?

Gard

Chadsalt:

I just inspected some of the tires I use. Four different sets and manufacturers all 265/75/16 "E" range . Each manufacturer had a different load rating at  a maximum pressure of 80 psi. The range in load carrying capacity was over #400 from the least to the most.

Gard

Notice I said "should".  My spare - spare is a Chinese job, has some off the wall load spec and is missing some DOT markings.

Just making a point. Did you ever look at the profile of a radial tire on a vehicle going around a corner? If it's a hard corner, the front tire is almost an "L" shape.

BOL  Gard

Gee...This is NOT the same FORD MOTORS that told all of the Explorer owners to run under pressured tires is it???...

Paul

Are you insinuating that 27psi isn't enough for a 4500# vehicle? What about comfort and a smooth ride? Isn't that important?

Gard

I agree, other than overloading a tire, about the worse thing you can do to it is run it underinflated.

BOL  Gard

Question...I am leaving out for a horse show tomorrow and got hubby to check tire pressure on truck and trailer. All were low on air. PSI is 80 on truck and trailer tires. He inflated them all to 75 and said that what it should be...why? I guess because he says so. He argues that if I inflate them to 80 PSI then load the horses on there, they will be overinflated. Am I going to be ok traveling on 75 PSI when sidewalls clearly say 80??

Unless you have an extremely heavy trailer and need every pound of carrying capacity, a five pound difference in air pressure won't be an issue. The trailer tires should be run at a max rated inflation for the best load factor.

If a tire is inflated to 80 psi, it will not matter what load is placed on it, the air pressure will not increase. It will only increase with temperature and that is why tires are checked for a cold inflation rate. The increase due to thermal expansion is considered by the manufacturer when he posts the pressures. That is why you should not let air out of a warm tire.

BOL  Gard

Thanks Dales.  That 3420 number - is that for a load range 'E' tire? 

I didn't see any chart on us-tra.org, just info on how to buy their $80 book of tire standards.

Thanks,

Tom

Getting back to the original question ...

Inflate your trailer tires to the maximum cold pressure stamped on the tire.  AND keep it maintained... Why??

You'll get the maximum load capacity, best fuel use, less wear,  and most security from tire failure or rim pull-off.

Who says ...  Carlisle, designer and maker of many trailer tires.  see here >>>  Carlisle recommends max pressure at all times.  see page 7 of this link >> http://www.carlisletire.com/product_care/proper_tire_care_safety.pdf

Tires on the tow vehicle have to perform differently than trailer tires.  I follow the truck builders recommendations for tire pressures.

Not that I disagree with max pressure in trailer tires.........BUT Carlisle also says not to exceed 60 mph. Apparently Carlisle makes an inferior grade product, not defective as in blow outs, but inferior as the "industry standard" for ST tires is 65 mph. So I take that into account when considering the rest of their "advice"