The advent of electronic ignition and an on-board computer has eliminated the need for regular tune-ups, but you still need to change your spark plugs. Many manufacturers recommend changing plugs every 30,000 or 40,000 miles (48,000 or 64,000 km) to ensure good fuel mileage and engine performance. Some new cars come with long-life plugs (sometimes called double platinum plugs) that can last for 100,000 miles (160,000 km). If your car isn't so equipped, make the switch after 30,000 miles. The extra cost is only a few dollars per spark plug. While you're at it, change your spark plug wires as well. Their typical life is 50,000 miles (80,000 km). Deteriorated wires can cause those high-tech new spark plugs to foul.