MBE 900 ENGINE 2007 OPERATOR'S GUIDE Winter Fronts A winter front may be used to improve cab heating while idling. At least 25% of the grill opening should remain open in sectioned stripes that run perpendicular to the charge air cooler tube flow direction. This assures even cooling across each tube and reduces header to tube stress and possible failure. Winter fronts should only be used when the ambient temperature remains below –12.2° C (10° F). All information subject to change without notice. (Rev. 04/08) 39 DDC-SVC-MAN-0040 0704 Copyright © 2008 DETROIT DIESEL CORPORATION