New tires:
Carlstar RadialTrail
ST175/80R13
65 PSI
Load Range D
Tent Trailer - Recommended Pressure > Tires' Max. Sidewall Pressure
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New tires:
Carlstar RadialTrail
ST175/80R13
65 PSI
Load Range D
New but wrong tires:
ST175/80R13
50 PSI
Load Range C
ST175/80R13
50 PSI
Load Range C
So now you have ST 17580R13 loadrange D
Maxload for single 1570 lbs AT 65 psi cold pressure wich is notthe maximum allowed cold pressure, that is higher. Continental groop puts in Europe also a 10 psi higher " maximum inflation pressure "on sidewall often.
And max speed of tire 130 kmph/81 mph, and dor tis speed the maxload is calculated.
To my opinion these OEM tires have still some poor reserves for the 3000 lbs GVWR minus 10% hitchweigt is 2700 lbs expected axleload wich is for many TT the GAWR.
Only found one brand, is Airstream, that has comfortable reserves in the tires to the GAWR , wich on its ( their) turn have comfortable reserve to the GVWR. The rest all yust enaugh to law. Those often popped rivets by using the referencepressure of tire.
Made you a cold pressure/ axleloadcapacity list, with build in maximum reserve , at wich no screws tremble loose. Then assuming total weight will come to 3000 lbs , or even more.
For that I will substract 3 loadindex steps ( 96 -3=93) to give tire a deflection as if it was a Q speedrated or higher, wich is calculated in maxload for 160 kmph/99mph.
Then give 90% of calculated axleload in list.
determined this to give that maximum reserves, absolutely needed, but still no screws trembling loose, or doors open up to things over the floor after the drive.
Will give it in next post
Maxload for single 1570 lbs AT 65 psi cold pressure wich is notthe maximum allowed cold pressure, that is higher. Continental groop puts in Europe also a 10 psi higher " maximum inflation pressure "on sidewall often.
And max speed of tire 130 kmph/81 mph, and dor tis speed the maxload is calculated.
To my opinion these OEM tires have still some poor reserves for the 3000 lbs GVWR minus 10% hitchweigt is 2700 lbs expected axleload wich is for many TT the GAWR.
Only found one brand, is Airstream, that has comfortable reserves in the tires to the GAWR , wich on its ( their) turn have comfortable reserve to the GVWR. The rest all yust enaugh to law. Those often popped rivets by using the referencepressure of tire.
Made you a cold pressure/ axleloadcapacity list, with build in maximum reserve , at wich no screws tremble loose. Then assuming total weight will come to 3000 lbs , or even more.
For that I will substract 3 loadindex steps ( 96 -3=93) to give tire a deflection as if it was a Q speedrated or higher, wich is calculated in maxload for 160 kmph/99mph.
Then give 90% of calculated axleload in list.
determined this to give that maximum reserves, absolutely needed, but still no screws trembling loose, or doors open up to things over the floor after the drive.
Will give it in next post
Here the list.
Used loadindex 93/ maxload 650kg/1433 lbs AT 65 psi, for reasons given in my former post #43.
In front of cold psi, for if you ever weigh the single axle, and behind the cold psi for total weight, expected 3000 lbs or more, of wich assumed 10% on hitch. Then you dont need to do pre- or after-calculations yourselfes.
"ONLY " need to determine total or axleweight 99% acurate, the most tricky part, and your responcibility.
It gives 3028 lbs totalweight at 69 psi, wich is my advice ( if not to much overloaded, for wich also reserve is build in a bit) and then it wont tremble screws loose , and even wear of tires.
List goes to 75 psi, reason also expained in former post.
This is for US , european TT's are made for lower percenntage on hitch, then I use 4% on hitch as standard.
Axleloadcapacity/ cold psi/ totalweightcapacity,
Used loadindex 93/ maxload 650kg/1433 lbs AT 65 psi, for reasons given in my former post #43.
In front of cold psi, for if you ever weigh the single axle, and behind the cold psi for total weight, expected 3000 lbs or more, of wich assumed 10% on hitch. Then you dont need to do pre- or after-calculations yourselfes.
"ONLY " need to determine total or axleweight 99% acurate, the most tricky part, and your responcibility.
It gives 3028 lbs totalweight at 69 psi, wich is my advice ( if not to much overloaded, for wich also reserve is build in a bit) and then it wont tremble screws loose , and even wear of tires.
List goes to 75 psi, reason also expained in former post.
This is for US , european TT's are made for lower percenntage on hitch, then I use 4% on hitch as standard.
Axleloadcapacity/ cold psi/ totalweightcapacity,
1121 | lbs/ | 26 | psi | / | 1246 | lbs |
1159 | lbs/ | 27 | psi | / | 1288 | lbs |
1198 | lbs/ | 28 | psi | / | 1331 | lbs |
1236 | lbs/ | 29 | psi | / | 1373 | lbs |
1274 | lbs/ | 30 | psi | / | 1416 | lbs |
1312 | lbs/ | 31 | psi | / | 1458 | lbs |
1350 | lbs/ | 32 | psi | / | 1500 | lbs |
1388 | lbs/ | 33 | psi | / | 1542 | lbs |
1426 | lbs/ | 34 | psi | / | 1584 | lbs |
1464 | lbs/ | 35 | psi | / | 1627 | lbs |
1502 | lbs/ | 36 | psi | / | 1669 | lbs |
1539 | lbs/ | 37 | psi | / | 1710 | lbs |
1577 | lbs/ | 38 | psi | / | 1752 | lbs |
1615 | lbs/ | 39 | psi | / | 1794 | lbs |
1652 | lbs/ | 40 | psi | / | 1836 | lbs |
1690 | lbs/ | 41 | psi | / | 1878 | lbs |
1727 | lbs/ | 42 | psi | / | 1919 | lbs |
1765 | lbs/ | 43 | psi | / | 1961 | lbs |
1802 | lbs/ | 44 | psi | / | 2002 | lbs |
1839 | lbs/ | 45 | psi | / | 2044 | lbs |
1877 | lbs/ | 46 | psi | / | 2085 | lbs |
1914 | lbs/ | 47 | psi | / | 2127 | lbs |
1951 | lbs/ | 48 | psi | / | 2168 | lbs |
1988 | lbs/ | 49 | psi | / | 2209 | lbs |
2026 | lbs/ | 50 | psi | / | 2251 | lbs |
2063 | lbs/ | 51 | psi | / | 2292 | lbs |
2100 | lbs/ | 52 | psi | / | 2333 | lbs |
2137 | lbs/ | 53 | psi | / | 2374 | lbs |
2174 | lbs/ | 54 | psi | / | 2415 | lbs |
2211 | lbs/ | 55 | psi | / | 2457 | lbs |
2248 | lbs/ | 56 | psi | / | 2498 | lbs |
2285 | lbs/ | 57 | psi | / | 2539 | lbs |
2322 | lbs/ | 58 | psi | / | 2580 | lbs |
2358 | lbs/ | 59 | psi | / | 2621 | lbs |
2395 | lbs/ | 60 | psi | / | 2661 | lbs |
2432 | lbs/ | 61 | psi | / | 2702 | lbs |
2469 | lbs/ | 62 | psi | / | 2743 | lbs |
2506 | lbs/ | 63 | psi | / | 2784 | lbs |
2542 | lbs/ | 64 | psi | / | 2825 | lbs |
2579 | lbs/ | 65 | psi | / | 2866 | lbs |
2616 | lbs/ | 66 | psi | / | 2906 | lbs |
2652 | lbs/ | 67 | psi | / | 2947 | lbs |
2689 | lbs/ | 68 | psi | / | 2988 | lbs |
2725 | lbs/ | 69 | psi | / | 3028 | lbs |
2762 | lbs/ | 70 | psi | / | 3069 | lbs |
2798 | lbs/ | 71 | psi | / | 3109 | lbs |
2835 | lbs/ | 72 | psi | / | 3150 | lbs |
2871 | lbs/ | 73 | psi | / | 3190 | lbs |
2908 | lbs/ | 74 | psi | / | 3231 | lbs |
2944 | lbs/ | 75 | psi | / | 3271 | lbs |
@jadatis, thank you for the work you've put into this!
I agree that the new (D load range) tires are close to the theoretical limit, but the owner is aware of this and plans to have the trailer loaded quite lightly, so nowhere near the theoretical maximum GVWR/GAWR of 3000#.
Per the placard shown in Post #3, the maximum trailer load is 808#, for a dry trailer weight of 2192#.
Let's assume they carry some, but not maximum, load, for a loaded trailer weight of 2500#.
Let's also assume the trailer is set up for a tongue weight of 10%. That takes the GAWR down to c. 2250#.
They should be fine.
I agree that the new (D load range) tires are close to the theoretical limit, but the owner is aware of this and plans to have the trailer loaded quite lightly, so nowhere near the theoretical maximum GVWR/GAWR of 3000#.
Per the placard shown in Post #3, the maximum trailer load is 808#, for a dry trailer weight of 2192#.
Let's assume they carry some, but not maximum, load, for a loaded trailer weight of 2500#.
Let's also assume the trailer is set up for a tongue weight of 10%. That takes the GAWR down to c. 2250#.
They should be fine.
First, I am very pleased with the responses to OP's question. I am glad so many people recognized that the trailer needed LR D tires.
The only thing I could add would be that the owner might consider using 14" tires and using reduced pressure. That would solve the marginal weight carrying problem - plus, the ride would be better for the stuff in the trailer. Of course, there has to be room under the fenders!
The only thing I could add would be that the owner might consider using 14" tires and using reduced pressure. That would solve the marginal weight carrying problem - plus, the ride would be better for the stuff in the trailer. Of course, there has to be room under the fenders!
Pop up trailer tires are tough but you must inflate them to what it says or they will get hot and blow out. Replace them only with the same load rated tires or you will be on the side of the road.
I'm a veteran of 10'' pop up trailer tires and on snowmobile trailers. Highest load range you can get for your size and inflate them to the cold pressure recommended. Balancing is the key to long life and happiness with these little tires along with respecting the speed rating of them. I run E rated tires on mine, they are out there. I have a bubble balancer and since balancing these tires I haven't had a roadside failure in decades.
They age out, cracking, before they blow out now. Not fun changing a trailer tire on the shoulder in a snowstorm.
Trailer tires are the most neglected tires on the road.
They age out, cracking, before they blow out now. Not fun changing a trailer tire on the shoulder in a snowstorm.
Trailer tires are the most neglected tires on the road.
I wondered if going up from 175 to 185 might help, but didn't suggest it, thinking it would be best to stick with the factory recommendation.
When the owner phoned yesterday morning, I speculated that the wheels would be 10". I was pleased to see they were 13".
I believe the original Austin Mini had 10" wheels.
My '70 Corolla had 12"ers.
Nick1994
$100 site donor 2024
Glad to see he got the correct tires.
My trailer isn't too heavy, but I still put Load Range D tires on it and run it at 60-65 psi. Same Carlisle's.
My trailer isn't too heavy, but I still put Load Range D tires on it and run it at 60-65 psi. Same Carlisle's.
Update: The store that sold the wrong tires has now taken them back and has reimbursed my friend most of the cost.
Not ideal, but a realistic outcome.
Not ideal, but a realistic outcome.
ls1mike
$50 Site Donor 2025
Those tires are pretty good. Like I said I run them on my travel trailer. It is 32 feet long (35'10" overall) and has 14 inch tires on in it. 205/75 R14.
I have never had a tire problem in 12 years, I did have an axle problem. (spindle was off a few degrees which caused side loading.)
My trailer originally came with load range C tires. 7040 total. Again they were accounting for what was on the tongue. Never liked the first set of tires.
At any rate those tires will be fine for his application. They just need to keep them properly inflated. I am glad the other store refunded your friend's money. It was the correct way to handle it.
I have never had a tire problem in 12 years, I did have an axle problem. (spindle was off a few degrees which caused side loading.)
My trailer originally came with load range C tires. 7040 total. Again they were accounting for what was on the tongue. Never liked the first set of tires.
At any rate those tires will be fine for his application. They just need to keep them properly inflated. I am glad the other store refunded your friend's money. It was the correct way to handle it.
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