Coolant

Base Radiator
Without Aux Rear Heat 16.4 quarts (15.5 L)
With Aux Rear Heat 19.0 quarts (18.0 L)

Heavy-Duty Trailer Tow Radiator
Without Aux Rear Heat 16.9 quarts (16.0 L)
With Aux Rear Heat 19.5 quarts (18.5 L)