The standard tires from factory meet the minimum requirements for the coach; they are E rated ST tires. I am not sure of the brand name, and the factory has the flexibility of selecting a new one without restrictions. That being said, some question the quality and quality control of previous tires that have come on HL units (foreign made). On the larger 5vers, I would not hesitate to upgrade to Goodyear G614's from factory. The increased rating (G rated) is well worth the "insurance" against possible blow out and trailer damage due to flying rubber. You more than likely have already thought of this, hence your question.......
As mentioned in other threads a good tire pressure monitorins system (after OEM - like TST 507) adds another level of insurance and peace of mind.
Some members have also upgraded to 17.5" tires AND rims, but this is more cost than just the factory upgrade option of G614s.
Hope this helps,
Brian