1997 Ford Aerostar Owner's Manual - Page 255
1997 Ford Aerostar Manual
Page 255 highlights
If your vehicle has aluminum wheels, you may demount the full size, non-temporary spare tire (if so equipped) and remount on an aluminum wheel to rotate the spare tire into your vehicle's rotation pattern. Rebalance the wheel. You may discover uneven outside shoulder wear on your vehicle's front radial tires if you drive often in the city and turn frequently around curbs. You can extend the life of your front tires by remounting them so the outside of the tire faces inside on the wheel rim. Replacing the Tires Replace any tires that show wear bands. When your tire shows a wear band, it has only 1/16 inch (2 mm) of tread left. Wear band Because your vehicle's tires may wear unevenly, you may need to replace them before a wear band appears across the entire tread. Your wheels and tires are match-mounted for improved ride. Before you begin to repair a tire, mark the wheel and tire so that they are properly aligned when remounted. This will ensure that the tires will continue to give you the same ride level. 256