Passenger car tire load ratings

[airdvr1227]

I've read plenty about using trailer specific tires. I was researching load ratings and started wondering. Let's use my rig as an example.

Trailer weight 1,000 lbs
Boat weight 3,700 lbs
Misc gear 500 lbs

Total 5,200 lbs

On a tandem axle trailer is it reasonable to say the weight on each tire would be 1,300 lbs? If that's true why wouldn't a passenger car tire with a load rating above 1300 lbs be OK?

 

[Silvertip]

Re: Passenger car tire load ratings

You are looking at just one factor in tire selection. Car tires are rarely inflated to their maximum rated pressure and they are constructed for handling, ride, and traction. They have relatively soft and flexible side walls. A trailer is often loaded to within 75% or greater of its maximum load capacity. Car tires therefore would create a great amount of heat from their flexing which they do not experience on a car. Tandem axle trailers do not "steer" around a corner like a single axle trailer -- they are literally "dragged" around the corner so there is terrific cornering stress on the tires that passenger car tires would not tolerate well. If this were a safe practice, trailer specific tires would not be manufactured as nobody would buy them. Yes - people use car tires on trailers but they are either poorly advised about the potential issue or the load they are hauling is extremely light.

 

[Lion hunter]

Re: Passenger car tire load ratings

Another potential issue that I have heard of is the UV inhibitors in trailer tires VS car tires. Trailer tires have more UV inhibitors that allow the to last longer and not dry rot. Car tires are usually wore out before dry rot sets in, so it's not as big a concern. So in the end, even in a light load, your probably cheaper if you go with the trailer tires.

 

[Navy Jr.]

Re: Passenger car tire load ratings

Something not mentioned very often is that the maximum load range of a passenger tire is diminished by 15% if it is used for trailering. This is according to the user manual that came with our new tires.

 

[Lion hunter]

Re: Passenger car tire load ratings

Something not mentioned very often is that the maximum load range of a passenger tire is diminished by 15% if it is used for trailering. This is according to the user manual that came with our new tires.

Thats interesting. Is that if you tow woth passenger tire on your car or have them on the trailer?