SUMMARY: This document responds to two petitions for reconsideration of a May 12@ 2009 final rule that upgraded the agency's safety standard on roof crush resistance. The first petition requested the agency to reconsider its decision to apply a lower roof strengthto- weight ratio requirement to heavier light vehicles@ i.e.@ ones with a gross vehicle weight rating greater than 2@722 kilograms (6@000 pounds)@ than to other light vehicles. The second requested reconsideration of that decision as well as the agency's decision not to adopt a dynamic rollover test requirement as part of this rulemaking. After carefully considering the petitions@ we are denying them. This document also responds to supplemental requests made by the petitioners.