I have had a tire issue of late and am thinking of replacing all four fiver tires. The Cardinal now has ST235/80R/16 Goodyear Marathon tires (made in China). My question is, can I replace the current tires with a LT235/80R/16 or an equivalent tire. If you have any replacement tire recommendations please let me know.Thanks

Since they are 16's, I would definitely go with LR E

Replacing the problematic ST tires with a LT has always been a excellent upgrade for eliminating ST tire issues for all types of trailer owners. Your ST235/80-16 E at 80 psi are rated at 3400-3500 lbs capacity. However which LT depends on your trailer axles rating. A LT235/85-16 E 80 psi at 3042 lbs capacity works great on 6k axles. If your trailer has 7k axles then tires like the Goodyear G614 or Sailun S637 are popular sizes in the LT235/85-16 G load range at 3750 lbs capacity and 110 psi. Some folks with 7k axles on their trailers have moved on up to the 17.5" LT tires and wheels.

6000 pound axles? Then any of the better quality LT tires will serve you very well.7999 pound axles? Then your best option is to upgrade to 17.5 inch tires and wheels.There are probably 100 pages on this subject just in the past six months. Use the search function above for hours of reading.

First, there is no LT235/80R16 - and this fact causes all sorts of discussion.It is likely that you can replace your ST tires with a larger LT235/85R16, but you will need about an inch more clearance around the circumference.Some folks have pointed out that an LT245/75R16 is closer in diameter to the ST 235/80R16, but they frequently forget to point out that it is wider by 5/8" when mounted on the same wheel - AND - it requires a minimum of a 6 1/2" wide wheel.Then there is the issue of load carrying capacity. An ST235/80R216 Load Range E has a maximum load carrying capacity of 3420# at 80 psi, while an LT235/85R16 LRE is 3042 # at 80. (same for the LT245/75R16 LRE).There is one school of thought that says you need to replace those ST's with something of the equivalent load carrying capacity - and that means a Load Range F (3415# at 95 psi) or a Load Range G (3750# at 110 psi.) - which are kind of hard to find.With that approach, there might be an issue will the wheels - although some say that the load is what is important and the inflation pressure not so much - that if push came to shove, it would be preferable to use more inflation to get the load carrying capacity in the tire. In other words, which would be worse, not enough load carrying capacity in the tire or exceeding the inflation pressure limit of the wheel? In either case, there is a risk of failure - and it can be pointed out that we are aware that tires fail regularly, but we are unaware of any recurring wheel failures.But there is another school of thought that says that an LT235/80R16 has a larger load carrying capacity because it is speed restricted to 65 mph - and that if you use an LT235/85R16 in its place(which is not only larger in diameter, which equals larger load carrying capacity, but also has a much higher speed rating), it is actually a step up in load carrying capacity.You may find tire dealers who would refuse to mount an LT tire in place of an ST tire - a problem you can avoid by having the tires changed individually.Now this topic is quite the source of discussion. I hope I have covered the issue without bias. The choice of how you want to look at this is up to you.

Replacing the problematic ST tires with a LT has always been a excellent upgrade for eliminating ST tire issues for all types of trailer owners. Your ST235/80-16 E at 80 psi are rated at 3400-3500 lbs capacity. However which LT depends on your trailer axles rating. A LT235/85-16 E 80 psi at 3042 lbs capacity works great on 6k axles. If your trailer has 7k axles then tires like the Goodyear G614 or Sailun S637 are popular sizes in the LT235/85-16 G load range at 3750 lbs capacity and 110 psi. X2 for the Good Year "G" rated tires!!!!! My new Big Horn 5th. wheel had Tow Masters, I told the dealer "no Sale" unless they replaced them with the GY "G" rated tires. Job was done and I am a happy camper:)

Tire Choice | Good Sam Community

fj12ryder
Explorer III
Sep 22, 2013
Actually it's not unusual for different makes of tires with the same label size to vary in actual diameter. That holds true for trailer tires, bike tires, and car tires. The actual size can vary quite a bit from the labeled size.

But I have the Sailun tires and they are indeed about 31 1/2" in diameter.
ken_white
Explorer
Sep 22, 2013
JIMNLIN wrote:
h2guy wrote:
Keep in mind, if you go to the G rated tires, the Sailun 637 is 2 inches larger in diameter than the GY 614. Can easily impact tire spacing.

Goodyear says the LT235/85-16 G614 is 30.7" diameter.

Sailun says the S637 235/85-16 G is 31.7" diameter.

Yes, both tires are 31.7" in diameter or GY is not labeling their tires correctly.

235 mm is the width -> 9.25"
85 is the aspect ratio, height/width -> .85 x 9.25" x 2 (top and bottom heights) = 15.72"
Rim Diameter -> 16"

Tire height -> 16" + 15.72" = 31.7"
JIMNLIN
Explorer III
Sep 22, 2013
h2guy wrote:
Keep in mind, if you go to the G rated tires, the Sailun 637 is 2 inches larger in diameter than the GY 614. Can easily impact tire spacing.

Goodyear says the LT235/85-16 G614 is 30.7" diameter.

Sailun says the S637 235/85-16 G is 31.7" diameter.
Lantley
Nomad
Sep 21, 2013
h2guy wrote:
Keep in mind, if you go to the G rated tires, the Sailun 637 is 2 inches larger in diameter than the GY 614. Can easily impact tire spacing.

While I agree sizing is a concern,
The Sailun is easily $600.00 or more cheaper than the GY.
h2guy
Explorer
Sep 21, 2013
Keep in mind, if you go to the G rated tires, the Sailun 637 is 2 inches larger in diameter than the GY 614. Can easily impact tire spacing.
Me_Again
Explorer III
Sep 21, 2013
Us out West wrote:
Scheduled replacement????
Yes these tires have a built in variable replacement schedule! One or more announce to the user when it is time to replace the others. chris
Us_out_West
Explorer
Sep 21, 2013
Scheduled replacement????
usnret
Explorer
Sep 21, 2013
Chris,
Thanks for ALL the info. Thankfully, I did not have any damage, thanks to my pressure pro TPMS alerting me as soon as the tire began to have air pressure/high temp problems. I will up grade tires/wheels on the next SCHEDULED tire replacement. I do read the Cardinal Owners forum frequently.
Me_Again
Explorer III
Sep 20, 2013
usnret wrote:
Thanks to everyone who offered advice and info. I certainly received an education in trailer tires and wheels. Although I did not want to put the OEM GY Marathon ST235/80/16E back on the trailer, in the end I did. I am in a travel status in a small town and had quite a time being able to get a replacement. Hopefully, things will workout. The tires I an replacing are well over three years old and I don't know their history as I am the 2nd owner.

Thanks again

Goodyear Marathon's were the OEM tire for that vintage trailer. You should plan on doing something better in the next couple years if you are traveling a lot. Goodyear should have replaced the tire and paid for any trailer damage. That is one of the few pluses of using low end tires, in that Goodyear is good on warranty and paying for damage to the trailer.

Come join the Cardinal club!!!!! OH! I see you are a member already!!!

Chris
avvidclif1
Explorer
Sep 20, 2013
Me Again wrote:
FastEagle wrote:
Me Again wrote:

Michelin is doing that with the 215/75R17.5 XTA which is being installed OEM on 5th wheels. It carries a 100KM speed rating(62MPH), 120 inflation and 4805 lb load rating. Michelin is saying the speed can be increased above 62MPH by reducing the max load below 4805 lbs. This drives one posted crazy, however it is according to industry guidelines/standards. There are charts for some tires that allow extreme loads at very low speeds.

Quoted from the Michelin Truck Tire Service Manual. Bottom of the right column on page nine of the reference.

"The Tire And Rim Association, Inc (TRA) permit operating a 65 MPH rated tire at higher speeds with a reduced load and increased inflation. No such permission is granted by TRA for tires with speed ratings below 65 MPH."

Michelin Ref

FastEagle

Did Michelin respond to your letter about this and the XTA?

Chris

The problem with his information is it applies to large truck and trailer tires not the LT series. Read closely.

Actually that whole book is about big truck tires. No mention of LT.

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