Passenger tires on trailer

[Sawdusted]

Guys, I have a trailer which used to be a Scotty camper. Single axle. It has tires starting to rot. I bought this trailer used, and I noticed that the PO had put on passenger tires on it.

It has P205/75R15 tires on it now with standard load. 1900lb max load at 35 psi IIRC

Can I just replace them with passenger tires or should I go with trailer rated tires. I usually don't haul more than 1000-1200 lbs with this.

Thanks

 

[Donald]

Trailer tires should be used. Need to know the proper load rating. LT tires would be OK. I believe trailer tires have a stiffer sidewall. You do not need radials for a trailer, but they will not hurt.

 

[IndyIan]

I've run the same size tires for loads nearly double that size, but putting them at 35psi everytime I use the trailer and keeping my speeds down to 50-55mph. So for your use I wouldn't hesitate to replace with P tires again.
I'm sure many will go on and on about liability and accidents, but if you are that paranoid then you probably shouldn't be using that trailer at all. Some insurance lawyer might say it was a camper trailer before....

 

[Cup of Joe]

I have the same size tires on my trailer, they are 6 ply and rated for 65 psi not 35.

 

[SwampSurvivor]

You can get a 205/75-15 trailer tire for less than a 205/75-15 car/LT tire ... I'd rather have that.

Trailer tires also are made for lateral grip and have tread as such. Also much stiffer sidewalls for carrying heavier loads all of the time.

 

[BobsArmory]

Because of car tires having softer sidewall you may see more side to side shimmy (is that a word) in the trailer. The stiffer sidewalls of a trailer tire will help your trailer pull much better esp. under loads.

 

[Texan4Life]

seems like the car tires did just fine. Personally I like to compare tires online and find a tire that fits my intended usage/load rating/price point.

I usually try and get the highest load rating/load index I can get in that tire size.

In my experience the car tire always ends up cheaper with a similar load rating. Never had any problems, just remember to air them up to what the sidewall max psi is.

Also car tires are higher sales volume, I have seen some new trailer tires with some pretty old date codes.

 

[mrsilv04]

Car tires on a single axle, flatbed utility trailer... you're fine.

Car tires on a single axle, camping trailer (with a higher center of gravity)... then I'd stick with trailer tires.

 

[Sawdusted]

Originally Posted By: mrsilv04
Car tires on a single axle, flatbed utility trailer... you're fine.

Car tires on a single axle, camping trailer (with a higher center of gravity)... then I'd stick with trailer tires.


Camper was demolished (Tree fell on it). It's a flat bed now

 

[FZ1]

Trailer tires,only. Replace every 5-6 years.

 

[CapriRacer]

I have spent a lot of time talking to RV'ers - and their opinion is that ST tires are to be avoided. They seem to fail way too often.

Many are moving to LT tires - but the problem here is sizing. There is very little commonality - especially in 15".

Also, many are using P metric tires, but they have to be derated by a factor of 1.1 if used on a trailer.

So to answer the OP's question, Yes, I think using Passenger car tires is OK in your application. Just inspect them on a regular basis.

 

[durallymax]

ST tires suck, LTs are much better, however I would compare the load rating of the P metrics and decide from there.

 

[IndyIan]

Originally Posted By: CapriRacer
I have spent a lot of time talking to RV'ers - and their opinion is that ST tires are to be avoided. They seem to fail way too often.

Many are moving to LT tires - but the problem here is sizing. There is very little commonality - especially in 15".

Also, many are using P metric tires, but they have to be derated by a factor of 1.1 if used on a trailer.

So to answer the OP's question, Yes, I think using Passenger car tires is OK in your application. Just inspect them on a regular basis.

So would you say that the OP tires would be good for 3400lbs? I found they start to look abit overloaded and heating moderately with 2400lbs.

 

[CapriRacer]

Originally Posted By: IndyIan
Originally Posted By: CapriRacer
I have spent a lot of time talking to RV'ers - and their opinion is that ST tires are to be avoided. They seem to fail way too often.

Many are moving to LT tires - but the problem here is sizing. There is very little commonality - especially in 15".

Also, many are using P metric tires, but they have to be derated by a factor of 1.1 if used on a trailer.

So to answer the OP's question, Yes, I think using Passenger car tires is OK in your application. Just inspect them on a regular basis.

So would you say that the OP tires would be good for 3400lbs? I found they start to look abit overloaded and heating moderately with 2400lbs.


Well, you forced me to do the math.

A P205/75R15 Standard Load has a rated load carrying capacity of 1598# at 35 psi. That means its rated load carrying capacity for trailer use is 1453#. I like to use a 15% reserve in tire loading, so the usable maximum load is 1235#. And assuming the load is not more than 10% side to side variation, that makes the load limit 1111# per tire.

Assuming there are 2 tires, and that the tongue weight is 10%, then I think the GVW of the trailer should be less than 2470#. Since the OP said he doesn't haul more than 1200#, that means his empty trailer can weigh up to 1516# - and that's a reasonable value for a small utility trailer.

And to answer your question: No, I don't start off with the same values the OP did and I certainly don't wind up with the end result you got.

 

[IndyIan]

I was going off the sidewall rating of 1900lbs, then derated to the 1700lbs for your 1.1 safety margin. But what you've calculated in your last post matches my experience. 1200-1300lbs / tire is all I want tow on those tires.

 

[CapriRacer]

Originally Posted By: IndyIan
I was going off the sidewall rating of 1900lbs, then derated to the 1700lbs for your 1.1 safety margin. But what you've calculated in your last post matches my experience. 1200-1300lbs / tire is all I want tow on those tires.


I don't get where the sidewall says the rating is 1900#. Nothing I can find leads me to believe this is true.

 

[Ken2]

Will a 235/75R15 XL tire fit? 109T service description. 2271# @ 50 psi.

 

[Rand]

if 215/75R15's fit

There are some LT tires available in that size.

 

[Hokiefyd]

I agree on avoiding ST tires and using either P-metrics or LT tires (depending on the situation). In theory, ST tires are designed for the task at hand, but it seems that you simply can't find any good quality ones, and there are many many reported failures of ST tires. The point of buying dedicated trailer tires is to reduce the likelihood of a failure, not to increase it.

I have P-metrics on my 5x8 trailer...specifically P205/65R15s. They're cheap Primewells installed by the previous owner. I must say, they've been good tires. They have absolutely no signs of weather rot (and they're at least 5 years old). They hold air extremely well (I rarely have to add any). I have no idea how they ride, but they've been good for the trailer so far. Yes, made in China.

 

[IndyIan]

Originally Posted By: CapriRacer
Originally Posted By: IndyIan
I was going off the sidewall rating of 1900lbs, then derated to the 1700lbs for your 1.1 safety margin. But what you've calculated in your last post matches my experience. 1200-1300lbs / tire is all I want tow on those tires.


I don't get where the sidewall says the rating is 1900#. Nothing I can find leads me to believe this is true.

In the original post, and I recall my tires saying the same thing but a quick check online shows that this size typically has a 1609lb load rating. Maybe I got the 6 and 9 mixed up?