Calls by Navistar and OOIDA to delay EPA's 2010 legislation were rejected by the EPA who insisted that it would stay on course for a 1 January 2010 implementation date. Volvo and Mack both released statements to support this decision having invested significantly into developing solutions in time for 2010. Per Carlsson, President of Volvo Trucks North America, emphasised the environmental and financial benefits of SCR, which is central to EPA10 and added, "Our testing and real-world experience demonstrates SCR is the optimal solution."