The second generation for the Jeep Wrangler kicked off in 1997 and ran all the way through the 2006 model year. The 2003 Wrangler had two engines available: a 2.4-liter four-cylinder and a 4.0-liter six-cylinder. Both of these engines required the same type of coolant, but the amounts needed to fill their respective cooling systems varied slightly.
Jeep recommends using only Mopar HOAT Antifreeze/Coolant 5-year or 100,000-mile formula in the 2003 Wrangler. Jeep recommends combining this coolant with water in a 50-50 mix for temperatures as low as -37 degrees F. If the temperature will be below -37 degrees F, then you may increase the amount of HOAT Antifreeze/Coolant up to 70 percent. The 2.4-liter engine's cooling system holds 2.7 gallons of the mixed coolant, and the 4.0-liter engine holds 3.2 gallons.
