One way to ensure a safe trip is to have the correct tools to support your travels. They would include a proper air pressure guage, tools for a tire change, and a basic tool set for ancillaries. They are available at any Walmart, auto, hardware and big box stores. You will feel much more secure in your travels, knowing that you have the knowledge and tools to handle most routine maintenance items.

Proper tire pressures are critical. Over or under pressures will greatly decrease a tire's life span and carrying capabilities. They can endanger your life and those of your prized possesions. A visual check cannot determine a tire's suitability. Only by accurately measuring the actual pressure, and knowing what it should be, can you determine if your trip will be safe or not.

Proper maintenance is critical to your safety, peace of mind, and wallet. A few well spent minutes will enhance all of them.

You ARE way off ..  (Gently ... lol)

The 80R16 is part of the tire size.  There should be a number in front of the 80

Look at the tire side wall again.  There is a max inflation pressure molded in.  That is the cold inflation pressure you should use.

[QUOTE]Originally written by mchew on 2011-11-16 6:55 AM

the tires are 80R16 - so doesn't that mean 80 lbs of pressure? my tire gage only registers to 65 lbs, which is why I don't use it. Am I way off??

NO! That number is for the sidewall profile series. If you carefully inspect the sidewall area, you will find a series of numbers that will read, " max inflation xxx psi, max loading xxx#s, number of plies xx, ply rating xx". The max inflation number is what you are concerned with for now.

You may in fact have an "E" rated tire, which does use a maximum of 80 PSI. But the numbers you referenced are the designation for the tire size. You will need to purchase a guage that covers the 80 # pressures range your tires may use.

$90 per tire doesn't seem right. I would recommend replacing your tire with a 16' truck LT radial tire, not a ST trailer tire. And at that price, I can't help but wonder if it's a Chinese brand, which I would not champion under any circumstance.

A quality American made LT tire in an "E" range, is usually in the $150 -$200 pricing, unless you like Michelins which are about ~20% higher. Yes, the higher in the alphabet, the more ply ratings of which the tires are constructed, and theoretically the higher the load rating they will carry.

F rated tires will have a higher rating and run higher air pressure. The problem with mixing them is that somebody may look at the tire and see the 100 psi listed on the tire and assume that is the same for all the tires on the trailer.  You might then over inflate the other 3 "E" rated tires.  It's scary to mix and match tires.

The other concern is that if the "F" tire shows a higher pressure and you inflate the tire to that pressue, You may over pressure the rim.  Most rims just are not rated for 100 or 120 psi tires.  When you upgrade a trailer to "G" tires for example, You usually also upgrade your rims to a stronger wheel. The minimun is that you usually replace the standard rubber valve stem with a metal valve.

The point being, that some body could read the side of the "F" tire and assume the pressures listed on the side of the tire are safe and try to inflate the tire to those levels.

As far as the price, I've bought 235/85r16 michelin tires and once in a great while the tire dealer has given me a screamin deal at $100.  So the $100 price doesn't automatically make it a bad tire, But in general Gard is correct that quality tires in that size will probably be higher.

If you don't already own on, buy yourself any early Christmas present in the form of a high quality cordless impact wrench.  Include impact sockets to fit both your trailer and your truck.  Carry an extra battery with you also. 

I purchased one for my wife several years ago (DeWalt); along with a Trailer Aid; because she goes solo or with gal friends more than when I can go.  It makes tire changing pretty effortless with that impact wrench.

Gard -     The ST235/80R16 LRE tire is rated at a higher load capacity than the LT235/85R16 LRE tire.  It also has a little different sidewall construction than the LT.  It is made specifically for trailer use while the LT is a truck tire.  The ST 16" tire was not available until just a few years ago.  The ST 15" tires have been in use on trailers for many years. 

Differences in brand and quality apply to all sizes.  Most new horse trailers and many of the higher end utility trailers with 6k or larger axles are coming through with the ST235/80R16 LRE or LRG tires.  There is little cost difference in the aftermarket between the ST and the LT tires, but we cannot buy one for resale for $100.  I would be suspicious of a mounted 16" tire for $100 or under and would assume that it is a low quality import.

I prefer the LT tires over a ST tire for a few reasons: Most ST tires are speed rated, many at a velocity less than the speed limits of most interstate roads. If a blowout occurs at any higher speed than its rating, the manufacturer can claim it wasn't at fault. It's like a U Haul trailer that has marked in larger letters, "max speed 55 MPH" as it is seen being pulled down the highway at 70 MPH. The second is availability. Most tire shops in our area don't stock ST tires, and if they do, the sizes are limited, and the manufactures are usually a choice of one.

There has been often a controversy over the sidewall construction of ST tires when compared to LT tires, with the ST advocates claiming to have superior side wall strengths. I offer a couple of examples. How much stress do you think the front tires' sidewalls of a diesel pickup encounters, when the wheels are turned at speed? What happens to the rear tires of a pickup when a BP trailer is being pulled, and the truck stops or slows whilst in a turning situation? What happens to the sidewalls when the truck is loaded with a full sized camper and is hit by sidewinds, or the bow wave of an oncoming tractor trailer?

In all of these instances, the LT sidewalls maintain a stable footprint and do so reliably for tens of thousands of miles. For anyone to say that when they are installed on a trailer, they can no longer maintain these capabilities, would be a disservice. A trailer doesn't turn as sharply as the pulling vehicle, generally has a lower center of gravity when its loaded, and has two axles close together reducing the shock of a hole or dropping off the pavement. A truck has support only at each end, and the tires are subject to more individual loading and terrain differences.

Upgrading from a "D" to an "E" range tire will increase its sidewall stiffness, and its weight carrying capacity. One advantage of the 16" LT tires is the wide availability of various aspect ratios, and the way you can purchase different tires for your individual needs. An 80 series tire can often be replaced with a 75 or 70 series tire. The lower sidewall heights will increase the sidewalls' resistance to flexing, albiet at a slight cost in ride quality. The widths can also be altered, increasing the weight capacity and its capability. The lower and wider the tire, the more capacity it offers.

LT tires usually provide many miles of reliable service, often dying of old age before they wear out, when they're installed on trailers. I have heard of very few trailers encountering blow outs, after the ST tires were replaced with LT tires. Yet it is not uncommon to hear of continual problems with ST replacements, even when they were replaced with better brands.

I beleve this was caused by both, speeds in excess of their designs, and the heavier sidewall constructions. When a tire is loaded, the heat travels from the thread to the sidewalls, and then to the bead. The sidewalls and the bead areas are the heaviest contruction of a tire. Once the heat travels to these areas, it can't escape and builds up. If it continues, the tires will overheat. This will cause the sidewall carcass to delaminate and results in a blow out.

The LT tires are intended for higher speeds, and are made to flex with less heat build up, resulting in a reliable opperation. These tires are made by many reputable American manufactures, and are widely available from many sources.

Well gard and I are actually in agreement about something.  Typically ST tires suck.  Reality is an ST tire has to pass very lenient tests to receive its rated capacity, compared to a LT where the testing is much more strenuous.  The actual testing specs can be found at the FMSCA web site; http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?reg=571.109   and   http://www.fmcsa.dot.gov/rules-regulations/administration/fmcsr/fmcsrruletext.aspx?reg=571.139 

Essentially it boils down to the ST being rated at a greater % of it's failure limit.  Sort of like a rope with a breaking strength of 10,000 lbs will have a general working limit of ~4000 lbs, BUUUT when used as climbing gear (life line) it would only be rated at 1000 lbs.  In this case the LT is the life line.

Some info I seen on Discount Tire website... http://www.discounttire.com/dtcs/infoTrailerTireFacts.dos

 Looks like something submitted to them from Carlisle Tire.... Several statements that sticks in my mine are.

• Time and the elements weaken a trailer tire.
• In approximately three years, roughly one-third of the tire's strength is gone.
• Three to five years is the projected life of a normal trailer tire.
• It is suggested that trailer tires be replaced after three to four years of service regardless of tread depth or tire appearance.

Wish I could find a LT225-75R-15lrD light truck tire with a smooth non-agressive tread.

I usually travel by myself and meet friends for vacations so being prepard for a blow out is important to me.

Last year I had a blow out and some of the tips I received from this site I felt was helpful.  The best one for me was to have a shovel so I could put it under the tire to help lift it up.  I don't think  I could have done it by myself with out it.  I also purchased a heavy duty lug wrench and have a pipe to extend it.  Loved my trailer aid! 

I also purchased emergency triangles since the trailer I bought is 8ft wide so I could be legal.  Was very glad I did because I was on a Missouri highway with no shoulders and didn't have an option to pull off the highway and had to change the tire on the highway.  It was the quickest I've every changed a tire and was very thankful I was prepared.