Can ST235/85R16 Tire Size be Used to Replace 8.75-16.5 Bias Tire on a 1990 EZ Loader Boat Trailer

Updated 04/04/2011 | Published 03/31/2011

Question:

Can ST235/85R16 with a 16 inch steel rim be used to replace 8.75-16.5 bias tires on 16.5 inch rims on a 1990 EZ Loader boat trailer. Im having trouble finding the 16.5 inch tires

asked by: M. B

Expert Reply:

The 8.75-16.5 bias tire is not a trailer tire. For a tire to be rated for use on a trailer, the tire will need to have a ST (special trailer) prefix before the tire size or an LT prefix after the tire size. You might want to check if the 8.75-16.5 tire size is the correct tire size that is recommended for your trailer.

You will also want to check the weight capacity of your trailer or axle. The 1990 EZ Loader boat trailer will have a plate or sticker on it that will list the VIN number. The weight rating of the axle should be listed on that same plate or sticker. Also, the axle could have a tag or plate on it that will list the weight capacity.

You will want to make sure that the tires used on your trailer will have the correct load carrying capacity that will exceed the weight capacity of your trailer. The ST235/85R16 Karrier tire on the Kenda Tire and Wheel, part # AM32764, has a maximum load carrying capacity of 3640 lbs at 95 psi.

Another thing to check is clearance for the ST235/85R16 tire size. The overall height on the ST235/85R16 tire is 31.6 inches and overall width of 9.37 inches. The 8.75-16.5 tire you are using now has an overall height of 30.5 inches and overall width of 8.75 inches.

The last thing to check is the bolt pattern of your trailer. The # AM32764 is a ST235/85R16 tire on a 16 x 6 inch wheel that has a bolt pattern of 6 on 5-1/2 inches. The bolt pattern is measured from the center of one bolt hole to the center of the bolt hole directly across from it.

I am including a link to a FAQ page on trailer tires and a link to a page on how to measure your wheel bolt pattern.