View Full Version : Auto Tires on trailer

06-13-2007, 01:26 PM
I have found two tires that are 205/50 R15s that have more than 60% tread life left and was curious if there would be a problem fitting them on a set of 15 trailer rims? any suggestions?

06-13-2007, 01:31 PM
Probably not a good thing to do. I personally wouldn't put auto tires under my trailer.

06-13-2007, 01:52 PM
You are going to get varying responses here and some or going to be dead set in their own way. There are reasons for putting trailer tires on trailers. Trailer tires have a stiffer sidewall to prevent blowouts and to withstand the torquing that occurs on a trailer tire, which increases with the number of axles you have.

In My Honest Opinion, I would not put car tires under my trailer, but I tow ~7,000 miles a year and I have a tandem trailer. However, you can put money on it that if I only towed my boat 5 miles every weekend, that I would have the cheapest tires on there... just enough to handle the task. It is a personal call and depends on your usage.

06-13-2007, 01:52 PM
NO NO NO NO. The sidewalls are not strong enough, and the weight rating probably isn't anywhere close.

If it is a single axle trailer, there's definately no point in taking the risk.

That said, I have a car tire as my spare (long story, was in a pinch), and it got me home the last 2 hours of a road trip (on a tandem axle trailer), but I took it off as soon as I got back and could replace the blown tire.

06-13-2007, 01:57 PM
Don't do it! the short term money savings today will never outweigh the savings of the damages this purchase will make to your boat or possible human injury down the road. There really is a reason there are trailer rated tires.

06-13-2007, 02:04 PM

06-13-2007, 02:10 PM
Click on the website below, then make your decision..........I agree with Sodar, it depends on your personal usage............I know a couple of people that have used passenger car tires and have had no problems.

As far as the 50's and 15 inch tires, you'll need to check fender & frame clearance.


06-13-2007, 02:16 PM
I just installed 4 new Goodyear Marathons on my tandem. However, it had 4 auto tires on before, and they performed just fine (including the 900 mile drive from Chicago to CT). The previous owner towed a lot as well. Installing them on a single axle would be a little more risky (for the reasons mentioned above) but if youre towing mainly short distances and the load rating on the tires is sufficient, I dont think its a major concern.

06-13-2007, 02:30 PM
I did the car tire thing on my bass boat "once", that trailer swayed
back and forth to the point of white knuckle driving!! it was crazy.
some of the dirt roads took to lakes, couple of times I could see the side of the boat from the washboards and that was'nt from going
to fast either!!!

east tx skier
06-13-2007, 02:35 PM
Trailer tires, like many other things, are cheap insurance IMO.

06-13-2007, 03:28 PM
It can be done if the load range is correct. I'm sure TMC#1 can add to the details.

dog paw
06-13-2007, 03:39 PM
Here is a couple snippits of info

http://www.discounttire.com/dtcs/infoTrailerTireFacts.dos;jsessionid=FvxW3ZBHVFRY7B VpLC69PQNK7d52L91WWghQK30FM0Hj9ZzN


06-14-2007, 02:56 AM
I don't buy the load argument - If four p235-70R15 tires can carry my 5000 pound Explorer for 60,000 miles, they can certainly carry my 3500 pound Maristar and 1000 pound trailer. This, of course, doesn't apply to only a pair on a single-axle trailer.

Note that the Discount Tire link doesn't say not to put auto tires on a trailer, but it does state that under no circumstances should you put a trailer tire on a car. Note that ST tires are only rated to 65 mph.

I don't buy trailer tires having a harder life than car tires. Unlike a rear tire, which has to withstand both acceleration as well as braking forces, a trailer tire has to deal only with braking forces.

Several have mentioned the side loads on a trailer tire that are created when making a sharp turn - you've apparently never autocrossed. When you see asphalt marks past the tire shoulder and starting on the sidewall, you know you've created severe side loads on that CAR tire.

I do believe the stiffer sidewalls/less sway argument that some of the references make. It's the only reasonable argument that has been made - car tires have gotten softer sidewalls over the years to soften the ride. This can't be good for trailer stability, especially on single-axle trailers.

With all of the complaints people have made on this board over the years about trailer tires falling apart, I don't quite understand the fervent support for them.


88 PS190
06-14-2007, 04:15 AM
trailers have unique loading, they are not on independant suspensions, and they do get pivoted.

We trailer our boat maybe 9 miles total a year, 4.5 miles in for the spring, 4.5 miles out to store.

another 9 unloaded to put the trailer away, and it does have trailer tires.

The reason is outlined on that Trailer tires.com link.

Trailers on car tires will sway side to side more than trailers on trailer specific tires.

That is a bad thing. Ever been in a vehicle that starts oscillating due to trailer sway? it is scary stuff. Trailer tires help prevent that harmonic motion.

06-14-2007, 06:07 AM
It can be done if the load range is correct. I'm sure TMC#1 can add to the details.

Been there, discussed that!

06-14-2007, 12:06 PM
thanks everyone for the info.