K&N has designed a performance air intake system for the 2009, 2010 and 2011 Ford Flex 3.5L. K&N dynamometer tests show a 9.19 horsepower gain at 4914 RPM with use of this K&N air intake modification. K&N tests multiple vehicles for each air intake system it makes to ensure a consistent horsepower and torque gain. This video demonstrates the steps needed to install a power gaining K&N air intake into 2009, 2010 and 2011 Ford Flex models with the 3.5L engine. http://www.knfilters.com/video/77-2578KS_Install.html