I tested at a local shop a 2005 Patriot , but was unable to test a 2004, (did not realize at the time i was there he had 2004's??)they told me that they made a different type of cam (cam and a half) for the 2005's, they're 2004's were like about $150 cheaper than the new models,,i'm going to go back just to see if there is any real difference between the years before i buy.