Straight coolant concentrate will freeze. The freeze point of undiluted coolant will only be 8.6 °F (-13 ºC), causing you to have potential freeze point problems in the wintertime. Also, too much corrosion inhibitor could lead to inhibitor fallout, especially in those cases where SCAs (supplemental coolant additives) are added. Always dilute coolant concentrate with deionized water prior to use. If you would like to use coolant straight from the bottle without having to dilute, choose our 50/50 pre-diluted formulation.