RepairPal Certified shops can diagnose and repair your 2016 Chevrolet Impala Limited. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
"Severe Duty" schedules says to change your spark plugs at 97,500 miles. I'd say anywhere after 70,000 or 80,000 is a good time to think of changing them, but at least at 97,500 miles.