Can You Upgrade from ST205/75R14 to ST215/75R14 Goodyear Endurance Tires on a Rockwood Travel Traile  

Question:

Expert Reply:

Hi Bill! I completely understand wanting to avoid a blow out.

You are asking all the right questions but honestly I think you are already in pretty good shape with the Goodyear Endurance tires that came on the trailer. Those are one of the better trailer tires on the market right now in terms of reliability and blowout resistance, especially compared to a lot of the OEM tires RVs used to come with.

Your current ST205/75R14 Goodyear Endurance Load Range D tires like part # GY57QB (assuming they are load range D) are rated for 2,040 pounds each at 65 psi, which gives the four tires a combined capacity of 8,160 pounds. Since your trailer’s GVWR is 7,710 pounds, you already have a pretty healthy amount of extra capacity at about 450 lbs, built into the current setup.

If it is time to replace the tires anyway or you already have the larger ST215/75R14 tires on hand, the swap is generally possible as long as you have enough clearance around the tires and between the tandem tires themselves. The ST215/75R14 is slightly taller and wider overall, so the biggest thing is verifying you still maintain adequate clearance to the wheel well, suspension components, and the neighboring tire under full suspension travel. Ideally, I like to see at least 3 inches of clearance above the tire to the wheel well and at least 1 inch between the inside sidewall and suspension or frame components. Since your trailer is tandem axle, I would also want at least about 4 inches between the front and rear tires because the larger 215 size will slightly reduce that spacing. We also do not carry this size Goodyear Endurance tire.

The good news is both tire sizes are commonly used on 14 inch trailer wheels, so there is a good chance your existing rims can accept the wider 215 size assuming the wheel width falls within the approved range.

As far as using the ST205/75R14 as a spare while running ST215/75R14 on the trailer, yes, you absolutely can use one temporarily in an emergency situation to get off the road or to a service location. I just would not recommend running mixed sizes long term on a tandem axle trailer because the different tire diameters can affect load sharing between the tires and suspension, which leads to premature tire wear.

Side note, where do you like to take the Rockwood? I've always liked the Minilites.

expert reply by: Heather A

0

Bill C.

5/21/2026

Hi Heather, Thank you for getting back to me so fast. I had run the weight numbers but just wanted to see if you and E-trailer had any upgrade suggestions. Just so you know, I sent the same request to Rockwood/Flagstaff and their response was "The tires we installed have a track record of success for units in this weight range. Going bigger is probably a waste of money. With the TPMS allowing you to monitor the constant tire pressure and temps, we haven’t heard of any issues with the Goodyear’s we install." Most of our travels are to the Texas Hill Country from the Galveston area-- so less than 5 hours--and a couple of longer trips a year to Florida and other states. Just wanted to feel confident that there wasn't anything safety-wise related to the tires that I was missing or that you and Rockwood/Flagstaff had come across. Thank you very much for your help. Bill

Heather A.

5/21/2026

@BillC You are very welcome! I am happy to hear Rockwood is on the same page. Sounds like you have a really nice and well thought-out towing setup. Hope you continue enjoying those Texas Hill Country trips, that’s a great area to camp and travel through. Happy travels!