What causes a car to start missing at 60 mph? on 2001 Hyundai Accent

This Accent drives fine, but when you get to 60 mph, it starts missing. Do you know what the problem could be? Thank you very much

Asked by for the 2001 Hyundai Accent
Is it a lack of power, or does the engine truly run rough? It's kind of an oddity. Makes me think of an intermittent transmission slip or something like that. Might be best to have a road test with a local technician.

Click that link for a list of shops near you.
Thank you very much for your time & trouble.