Posted 2016-11-03 11:09 AM (#168814) Subject: Recommended PSI
Member
Posts: 28 Location: Miami, FL
Just bought a new set of LT235/85R16 BF Goodrich Commercial AT that have a PSI of 80. For an aluminum 3H - 8' short wall trailer (Bison Stratus 8308), can anyone recommend a proper PSI #? I keep reading that one should keep the tires at max PSI when cold ... But experience (& instinct) tell me otherwise - anywhere between 55-75?
Posted 2016-11-03 2:38 PM (#168817 - in reply to #168814) Subject: RE: Recommended PSI
Regular
Posts: 88 Location: Washington
Run 'em at the recommended pressure. You paid for the load rating and that rating is at 80 psi. I think the LT is a little more forgiving for shedding heat but not worth it to run lower.
Posted 2016-11-03 3:53 PM (#168818 - in reply to #168814) Subject: RE: Recommended PSI
Veteran
Posts: 108 Location: Lawrence KS
The 80 PSI is not the recommended pressure, Most likely it says Max pressure is 80 psi. ?The trailer manufacturer would be the one to recommend a pressure not the tire manufacturer. Just like on a car or truck. Say a 2005 Dodge 3/4 t recommends 65 psi on the front , just because you put a max rated 80 psi tire on it does not mean you automatically change the manufacturers recommend tire pressure.
?I run trailer tires at 65 psi and have never had a problem.
Posted 2016-11-04 8:19 AM (#168824 - in reply to #168818) Subject: RE: Recommended PSI
Elite Veteran
Posts: 801 Location: Tenn/Ala.
Steve-O - 2016-11-03 3:53 PM The 80 PSI is not the recommended pressure, Most likely it says Max pressure is 80 psi.
?The trailer manufacturer would be the one to recommend a pressure not the tire manufacturer. Just like on a car or truck. Say a 2005 Dodge 3/4 t recommends 65 psi on the front , just because you put a max rated 80 psi tire on it does not mean you automatically change the manufacturers recommend tire pressure.
?I run trailer tires at 65 psi and have never had a problem.
Well, Steve Os info is spot on. Any professional tire person will have a tire factory issued Tire & Rim Data book that will include a chart. For that size tire, there is a chart with weight & inflation pressures needed to carry that weight. Remember- air carries the weight. The tire's job is to carry the air. Tires that are run overinflated are too stiff, resulting in a harsh ride, and hard on the tire itself as it cannot flex as much on a pothole or curb. This became apparent some years ago in the commercial industry when they dropped inflations down to carry the weight, rather than the maximum PSI. Tires starting lasting longer. But that usually only meant going from 120 or 125 down to 110 PSI. And they get checked very often.
Your new BFG will rate at 3,042# per tire, which is 12,168 for all 4, on a trailer that weighs less. So I'm sure there is room to drop it.
But- as a dealer, we recommend running each tire at maximum pressure. Not to talk out of turn, but most folks don't check pressure very often. If that tire can live at 65 or so, starting at 80 gives some insurance against a slow leak or neglect. While some of us can inflate our trailer tires at home, we've found most folks cannot. And they just don't tote a loaded trailer to the tire shop very often. So as to get the most safety we feel we can for our customers, we generally start them at maximum unless asked differently.
Just my opinion, based on being a trailer dealer and a tire dealer for the past 30 or so years.
Posted 2016-11-04 3:34 PM (#168826 - in reply to #168814) Subject: RE: Recommended PSI
Extreme Veteran
Posts: 322 Location: Fort Madison, Iowa
From experience of having blowouts, I'd recommend running the maximum of 80 psi. I check my tires often around home and always check before going on vacation. After my last blowout, I started to check my air pressure before leaving the campground to come home, something I hadn't done before. Last year, I had a nine hour haul going and a week later I check my tires before leaving. All my tires lost air pressure averaging 6-10 lbs. I'm with RTSmith that by running the maximum you're covered if you lose air while traveling.
The other thing I found out was to make sure your ply is heavy enough for the load you're carrying. I had 10 ply tires and was at my maximum for the weight of the tires so I switched to 14 ply to carry my load.
Posted 2016-12-05 7:26 PM (#168939 - in reply to #168814) Subject: RE: Recommended PSI
New User
Posts: 2
Location: Lucas tx
Run them at 80! I had several blowouts until I learned that rule. Trailer tires are different than truck tires and many will void their warranty if you run them at less.
Posted 2016-12-13 4:11 AM (#168970 - in reply to #168814) Subject: RE: Recommended PSI
Expert
Posts: 3802 Location: Rocky Mount N.C.
Trailer Tire Facts
Trailer Tire Applications
Trailer tires are designed for use on trailer axle positions only. They are not built to handle the loads applied to, or the traction required by, drive or steering axles.
Inflation
Always inflate trailer tires to the maximum inflation indicated on the sidewall.
Check inflation when the tires are cool and have not been exposed to the sun.
If the tires are hot to the touch from operation, add three psi to the max inflation.
Underinflation is the number one cause of trailer tire failure.
Load Carrying Capacity
All tires must be identical in size for the tires to properly manage the weight of the trailer.
The combined capacity of the tires must equal or exceed the Gross Vehicle Weight (GVW) of the axle.
The combined capacity of all of the tires should exceed the loaded trailer weight by 20 percent.
If the actual weight is not available, use the trailer GVW. If a tire fails on a tandem axle trailer, you should replace both tires on that side. The remaining tire is likely to have been subjected to excessive loading.
If the tires are replaced with tires of larger diameter, the tongue height may need to be adjusted to maintain proper weight distribution.
Speed
All "ST" tires have a maximum speed rating of 65 mph.
As heat builds up, the tire's structure starts to disintegrate and weaken.
The load carrying capacity gradually decreases as the heat and stresses generated by higher speed increases.
Time
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.
Mileage
Trailer tires are not designed to wear out.
The life of a trailer tire is limited by time and duty cycles.
The mileage expectation of a trailer tire is 5,000 to 12,000 miles.
Why Use An "ST" Tire
"ST" tires feature materials and construction to meet the higher load requirements and demands of trailering.
The polyester cords are bigger than they would be for a comparable "P" or "LT" tire.
The steel cords have a larger diameter and greater tensile strength to meet the additional load requirements.
"ST" tire rubber compounds contain more chemicals to resist weather and ozone cracking.
Storage
The ideal storage for trailer tires is in a cool, dark garage at maximum inflation.
Use tire covers to protect the tires from direct sunlight.
Use thin plywood sections between the tire and the pavement.
For long term storage, put the trailer on blocks to take the weight off the tires. Then lower the air pressure and cover the tires to protect them from direct sunlight.
Maintenance
Clean the tires using mild soap and water.
Do not use tire-care products containing alcohol or petroleum distillates.
Inspect the tires for any cuts, snags, bulges or punctures.
Check the inflation before towing and again before the return trip.
Keys to Avoiding Trouble
Make sure your rig is equipped with the proper tires.
Maintain the tires meticulously.
Replace trailer tires every three to five years, whether they look like they're worn out or not.
Trailer Tire Warranty
The Carlisle trailer tire warranty applies to the original purchaser for three years from the date of purchase or until the tread depth reaches 3/32".
The OE (original equipment) warranty goes into effect at the time of the trailer purchase
Posted 2016-12-15 10:05 AM (#168982 - in reply to #168814) Subject: RE: Recommended PSI
Expert
Posts: 1989 Location: South Central OK
Seeing the above post and remembering why I changed to LT trires all those years ago...I can't remember when I've ever driven on a highway at 65MPH unless it's the posted speed limit. ST tires have a speed rating of 65MPH, drive faster than this number and it's trouble.
Posted 2016-12-17 9:20 PM (#168990 - in reply to #168982) Subject: RE: Recommended PSI
Member
Posts: 15
Location: SW OK
huntseat - 2016-12-15 10:05 AM Seeing the above post and remembering why I changed to LT trires all those years ago...I can't remember when I've ever driven on a highway at 65MPH unless it's the posted speed limit. ST tires have a speed rating of 65MPH, drive faster than this number and it's trouble.
That and the part about the expected life of ST tires being no more than 12000 miles. That might be fine if you pulled the trailer no more than that in the 3-4 years of life it says to expect, but when you pull it 10-12k a year, ST's don't dollar out over LT's.
Posted 2017-01-10 1:30 PM (#169096 - in reply to #168814) Subject: RE: Recommended PSI
New User
Posts: 2
Just wanted to let you know that in my experience I've found that overloading and under inflation are the BIGGEST causes for blowouts. It's important that you make sure that both your tire and rims are rated for the same PSI. What are your rims rated for? If they're lower then eventually down the road your rims are going to crack. I've been running 19.5 tire and wheels from Boar Wheel for the last two years and couldn't be happier. They are both rated for 110 PSI. They have a higher speed rating and load capacity too!
Posted 2017-01-10 1:30 PM (#169097 - in reply to #168814) Subject: RE: Recommended PSI
New User
Posts: 2
Just wanted to let you know that in my experience I've found that overloading and under inflation are the BIGGEST causes for blowouts. It's important that you make sure that both your tire and rims are rated for the same PSI. What are your rims rated for? If they're lower then eventually down the road your rims are going to crack. I've been running 19.5 tire and wheels from Boar Wheel for the last two years and couldn't be happier. They are both rated for 110 PSI. They have a higher speed rating and load capacity too!
Recommended PSI
