Replacement Special Trailer Tires to Replace Radials on Boat Trailer

Question:

my boat trailer new came with 4 ply raidial car tires I had them for 18 years I bout new ones they are cooper tires but only 2 ply can I use them

asked by: Billly S

Expert Reply:

Trailer tires rarely last much longer than about 6 years and that is the oldest we recommend a tire be before it is replaced. If you got 18 years of service from a set of car tires (!!!) you got lucky, but it surely is time for new ones, and they need to be special trailer tires.

The number of plies in a tire does not matter like it used to. Years back, the ply rating pretty much told you the whole story of a tire's capabilities, but with modern special trailer tires (the only type you should use on your trailer, by the way) the ply ratings no longer matter so much as load range. This is the actual amount of weight each tire can safely handle.

The Kenda bias ply trailer tire you referenced, 4.80-12 tire # AM10062, is a Load Range C tire that can handle up to 990-lbs per tire when installed on a suitable 12 x 4-inch wheel. This tire gives the equivalent of a 6-ply rating (although it doesn't actually use 6 plies in its construction).

Both radial and bias ply tires can be used on a trailer, so long as they are special trailer tires, and so long as you do not mix tire sizes or types. Always keep trailer tires fully-inflated to the psi pressure rating that appears on the tire sidewall. Radials tend to provide better grip and more flex, while bias ply tires are better for handling heavy loads and for off-road use, such as on a farm.

I have linked two helpful articles on trailer tires and also our main page for tires. You can click on the filters on the page to select your wheel diameter, tire size and tire type. I will be glad to help you select replacements if you care to tell me your current tires' size and load range rating.

expert reply by: Adam R