Received this from Sumitomo:
I’d like to assure you that the Sumitomo ST727 275/70r22.5 tire has been engineered and developed for use on North American highways. It’s true, the tread design is not specifically designed for RV use like other manufacturers. But rest assured that the casing integrity of this tire meets or exceeds the standards required of it for extended normal highway use up to 75 MPH. I believe you will see in comparing our load carrying capacities, tread depth and speed rating is comparable to other manufacturers tires in this size.
Sumitomo has a long standing quality reputation for technology; using the single ply of steel in the body, multiple layers of steel belt in tread, and a tread design that will resist irregular wear and give good fuel efficiency and stability. The ST727 is a proven performer.
Thank you so much for your interest in Sumitomo Tires. For additional information, please visit our website at sumitomotires.com