There are six different tire sizes for the 1998 Dodge Caravan, and the appropriate size depends on the model. The Caravans that had 14-inch wheels require a tire size of 205/75R14. The Caravan ES requires 215/65R16 tires. The Caravan LE and SE each had two sizes: 215/65R15 and 215/65R16.
Tire sizes contain four different pieces of information. The first number is the width of the tire in millimeters. The second number is the ratio of the height to the width. The letter after the ratio is the construction type of the tire, and the last number is the rim size in inches. For example, a tire size of 205/75R14 is a radial tire with a height of 205 millimeters, a height-to-width ratio of 75 and a rim size of 14 inches.