Is it safe to use the High Mileage Sea Foam oil treatment on an engine with 80,000 miles on it? [SOLVED]

Thanks for the question. Yes, you can use High Mileage in the oil of a vehicle with 80,000 miles on it. It will do a good job cleaning up oil residues and deposits. Add it 100-300 miles before your next oil change. Add 1 oz of High Mileage per quart of oil (and do not exceed that ratio).