Maintenance is the key to longevity. However, it is not necessary to vary far from the manufacturers recommendations. The manufacturers have worked to determine what is the best for their vehicles, and if you follow their FULL maintenance guide you will have a vehicle that will last past the 500k mark.
The number one waste of money and resources is premature changing of oil. If you have an old vehicle, match your use with the manual, and utilize annual lab work. If you have a modern vehicle with the maintenance reminder, follow it. Remember, maintenance is more than oil changes. It includes needed lubrication, ALL filters, belts, all fluids (more engine damage is done by out of date coolant than poor oil changes), and timely adjustments. People will still change their oil and filter every 2,500 - 3,000 miles, but they won't adjust or replace belts, and they ignore their coolant and timing belts.