Should 15" or 16" Tires be Used on Custom Boat Trailer for 7,500 lb Boat

Question:

Hello I am thinking of having a boat trailer built for my 27 ft sailboat which weighs between 7,000 and 7,500 lbs. Would you recommend using a 15 or 16 inch tire? Thank you.

asked by: Roy S

Expert Reply:

It really depends on how many axles you plan on using. As long as the combined weight rating of the tires on a single axle meet or exceed the weight rating of that axle then you are good to go.

For example, the 15" Karrier # AM10303 has a load range of E which is 2,830 lbs at 80 psi. When 2 of these are used on an axle that gives them a combined rating of 5,560 lbs. Naturally you will be limited by the lowest rated component so if you were to use 3 axles that are rated for 5,200 lbs (or even 3,500 lbs), if you were to use these tires the max weight would not increase to 5,560 lbs.

The 16" Karrier # AM10501 has a weight rating of 3,960 lbs at 110 psi with a load range of E. If you have these installed on a 5,200 lb axle it will basically just mean that these tires will not have to work very hard.

Unless you are really wanting 16" tires, you can definitely use 15" tires if you will be using 2 axles rated at 5,200 lbs. I recommend finding out what size axle you need for your application and then choose tires accordingly.

expert reply by: Jon G