What is the Difference Between 4.80/4.00-8 and 5.70-8 Trailer Tires for a Boat Trailer

Question:

My older boat trailer currently has 5.70-8 tires/wheels with the 5 bolt-4-1/2inch bolt circle. What is the difference between the 5.70-8 and 4.80/4.00-8 tires? The trailer/boat/motor/gear is around 1000 pounds so I dont need a heavy duty tire. Wondering if there is a benefit to choosing one versus the other. Thank you.

asked by: K.D. M

Helpful Expert Reply:

Both the 4.80/4.00-8 and 5.70-8 tires sizes will fit the same wheel size, 8 x 3-3/4 inch. The 5.70 is taller by 2 inches and wider by 1.2 inches. If you have more than 1 inch of space between the tire and a fender and more than 1.2 inches between the side of the tire and the trailer then you can use the larger size such as # AM10010 rated for 715 pounds at 50 psi.

If you do not have the space then stick with the same size you have, 4.80/4.00-8 using # AM10002 rated for 590 pounds at 60 psi or # AM10004 rated for 745 pounds at 90 psi.

expert reply by: Michael H

Kevin

8/5/2020

I have motorcycle trailer with 4.80-8 4 lug tires. I want to know what I can do to get the speed rating for 75mph and maintain using a 4 lug rim. I might be able to get a 10" tire on it but I don't think I can use a 12". Would it help to go to a 5.7-8 tire?

Chris R.

8/14/2020

To get that type of speed rating you'll definitely need to move up to a 10" tire/wheel. If you have enough clearance available, the Kenda 205/65-10 # AM3H370 will work well and it features an 81 mph speed rating. This will be about 4-1/2" larger in height/diameter (with only half of that difference actually affecting fender clearance) and 3.7" larger in width than your existing tires.