Replacing 4 instead of 5 tires on a used trailer?

The ST205/75R14 tire already gives me a 42% cushion. 1760#x4= 7040#. My TT's GVWR is 4950#. I'm guessing that's enough.

I do not want to spend money on new rims. My current aluminum rims are rated to 60psi. If my rims were rated to 65psi, I'd probably put the Kumho's on them. That would be an easy upgrade.

Lowsuv wrote:
instead of replacing all of the tires i spent the extra money ( saved by not buying a new spare ) to upgrade the load carrying tires an extra size and an extra load rating .
i picked up an extra 35 % in load rating capacity in pounds as stated on the tire sidewall . minimal cost while replacing .
i did this because i occasionally tow long distances starting at 5 pm and towing through the night . i do not want to change a tire in the dark .
i sometimes do this both directions to really far destinations .
i probably pick up an extra mpg or so due to no traffic and i certainly can average a couple of mph better also even at the same cruise setting .
we don't have a freeway in central oregon and it is mostly 2 lane US highways such as hiway 97 , 20 , 26 , and so forth .

instead of replacing all of the tires i spent the extra money ( saved by not buying a new spare ) to upgrade the load carrying tires an extra size and an extra load rating .
i picked up an extra 35 % in load rating capacity in pounds as stated on the tire sidewall . minimal cost while replacing .
i did this because i occasionally tow long distances starting at 5 pm and towing through the night . i do not want to change a tire in the dark .
i sometimes do this both directions to really far destinations .
i probably pick up an extra mpg or so due to no traffic and i certainly can average a couple of mph better also even at the same cruise setting .
we don't have a freeway in central oregon and it is mostly 2 lane US highways such as hiway 97 , 20 , 26 , and so forth .

The main reason I would like to replace them is I don't want to be all the way to Cali and have tires give out on me.

They are Goodyear's. I know the GY Marathons have nearly as bad a rep as the old Carlisle's do.

Wishin wrote:
If you were talking 5-10 year old tires, I'd replace the spare. That is what I did with my 10 year old tires when I bought my used trailer. Being that it will only be 3.5 years old, I'd keep it and just replace the 4. I'm not even sure I'd replace any of them at 3.5 years old unless you are really suspect of the tires. I have Maxxis on mine now and have had no issues since I put them on 4 years ago and unfortunately they were 3 years old when they were installed "new" so they are really 7 years from date of manufacturer. I'll replace them for next year at which point they will probably have about 10k miles on them before we take a long trip.

If you were talking 5-10 year old tires, I'd replace the spare. That is what I did with my 10 year old tires when I bought my used trailer. Being that it will only be 3.5 years old, I'd keep it and just replace the 4. I'm not even sure I'd replace any of them at 3.5 years old unless you are really suspect of the tires. I have Maxxis on mine now and have had no issues since I put them on 4 years ago and unfortunately they were 3 years old when they were installed "new" so they are really 7 years from date of manufacturer. I'll replace them for next year at which point they will probably have about 10k miles on them before we take a long trip.

If the tire was covered and not exposed to the sun it is OK. Just be sure to monitor the air in it like you do all the other tires.

tony - Strange blowout.

There is noticeable distortion on the near shoulder. I would guess that this was at least partially caused by a factory defect to begin with. Had it ever been on the road it probably would have failed prematurely

It's possible that the body plies themselves were defective (incomplete coating of the fabric with rubber or dry stock), or the tire builder made bad splices.

I am less inclined to believe it was rusty wire under the tread. It looks more like the sun caused a hot spot right on the top of the tire and the carcass eventually let go.

I guess it might help if a spare is stored in the shade under a trailer rather than mounted in the open in direct sunlight. The cover may block UV rays, but hot and cold temperature extremes still cause expansion and contraction enough to cause stress.

And in this case, that stress, combined with what appears to have been a less than perfect tire, pushed the tire to the breaking point.

Age alone would be my third choice as the root cause of the failure.

I am planning to replace my 4 trailer tires at the end of this season, and only because of age. They are 10 years old. They have great tread, no cracks, stored off the ground during winter, and covered for 9 months of the year. I will not replace the spare, it has not been off the back in 10 years.

"...The spare has been out of the elements and never carried any load. It could be used as a spare for a really long period. My father never put the spare on the road in his Lincoln Town Car for the first 10 years he owned it. Then he put it on and drove it for four more years. No problem.
Years back I had a friend that worked for Firestone (way before they became Bridgestone). He was an engineer at one of their plants and he told me they had a temperature controlled (and maybe humidity as well) store room where they kept an assortment of brand new tires including tires for small planes and even tires for model-T Fords that had the words "non-skid" for a tread pattern. These atypical tires were stored off the ground in racks basically forever just in case a need arose. "

Car tires are nothing like ST tires. They are both round and black but that's about the only thing they have in common. Construction and composition material are different as is the intended use.
Good Luck, Mike

After exploding a Goodyear on the highway, and having to change it on the side of a busy highway, and drive thru a desolate area at night with no spare. I'd get them all changed.

Easy call for me. I would keep the spare !!