I recommend moving to an all-steel tire for better durability. All steel tires have steel in the sidewalls, instead of polyester belts, that have the added benefit of protecting your tire should you scrape it against curbs. These tires are designed for commercial use where the vehicle can be operated fully loaded 24/7.
I switched to the Bridgestone Duravis M895 M+S rated tires a while back and have about 2000 miles on them. The weight per tire difference is significant, 53 lbs/tire for these tire vs 40 lbs/tire for the old tires.
The Bridgestones have a Q speed rating which is a limit of 99 miles/hr. The maximum sustained speed I have driven with them is 65 mi./hr.
Here is the tread pattern, note the sidewall protector ribs: