Did the 3900 change from 2006 to 2007? I thought the 3900 torque peak was at 2,800 RPM:
http://www.roadandtrack.com/assets/download/0602_pontiac_data_panel.pdf
But the Pontiac website now says 4,600 RPM.
http://www.roadandtrack.com/assets/download/0602_pontiac_data_panel.pdf
But the Pontiac website now says 4,600 RPM.