What is good or bad car mileage?

It mainly depends on the year model and how they drove it. if it is an 90 model car or older a hundred thousand miles is about it, but my friend has a 95 Chevy 1/2 gas engine and it has 560000 miles he says his secret it mobil one oil. if you change your oil when you need to and change your fuel filter every 30000 miles it could last forever, but i wouldn't buy a car 9o or newer still with over 150000 miles and make it an everyday driver.