What Size Wheels and Tires Should I Switch My Boat Mate Trailer to with SUV Wheels and Tires on it?  

Question:

Expert Reply:

Hello Greg,

You’re definitely on the right track here, and you’re not missing anything. The reason you’re having such a hard time finding an 18" option is because true ST (Special Trailer) tires are essentially not made in that size. Those larger setups are usually paired with SUV or passenger tires, which look good but aren’t designed for trailer use.

The difference really comes down to construction. ST tires are built specifically for trailers, with stiffer sidewalls to reduce sway, higher load ratings, and better heat resistance for long-distance towing. That heat resistance is a big deal, because excessive heat is one of the main causes of trailer tire blowouts. ST tires are designed to handle that constant load and dissipate heat better, which helps greatly reduce the risk of a blowout compared to passenger or SUV tires.

I’d recommend switching to a 15" wheel and ST tire setup. A great option is the Goodyear Endurance ST205/75R15 Radial Tire with 15" Eagle Aluminum Wheel, part # GY37QB that you mentioned. This combo is rated for 2,150 lbs per tire at 65 psi, giving you 8,600 lbs of total capacity on a tandem axle. That lines up really well with most wake boat trailers when loaded. For a center cap, you will want the Replacement Center Cap for 15" Aluminum Viking Series Wheels - Gloss Black # CXF106B.

It’s also worth noting you don’t want to go too high on capacity. A higher load range can make the tire much stiffer, which can lead to a rough, bouncy ride and transfer more shock into the trailer and boat. This Load Range D setup gives you a nice balance of capacity and ride quality.

I also saw you were asking about the Aluminum Trinity Series wheel, part # TA74XR, which is a 5 on 4-1/2" bolt pattern. I’m assuming that’s what you have, and the Goodyear combo matches that, so it should be a direct fit. If not, let me know your bolt pattern and I can find the right option, or we can look at hubs if you can share your axle capacity.

What body of water do you mainly go out on? I did wake boarding one time at Lake Havasu, I got up quick, stayed up for a while, but when I hit I realized I have my Father's knees, have to stick to the skis. Now I spend my time on a Bass boat chasing that 10 pound bass mainly at the lake of the Ozarks, and Mark Twain Lake here in Missouri =)

expert reply by: Kate F

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Goodyear Endurance ST205/75R15 Radial Tire w/ 15" Eagle Aluminum Wheel
(click to enlarge)

Greg B.

3/31/2026

Thank you that was very helpful! We go to Perris in SoCal as well as the river by Parker. Havasu a bit as well. Thanks!

Kate F.

3/31/2026

@GregB Very cool, I grew up in SoCal but call Missouri home now. I lived in La Mirada, Perris wasn't too far. If you ever have any questions in the future, you know where to find us.