I have found the answer on my own and decided to post it here for future reference. Chevrolet on this model has a "liftetime" fuel filter which is built into the fuel pump located in the gas tank. So in order to change the filter the whole fuel pump must be changed.
The 2007 Chevrolet Impala runs on flex-fuel (FFV).
I have a 2008 Impala LH and get 18.9MPG mostly city drivingI do not have the flex motor just the 3.5 V-6. My friend drives his Impala over the road a lot and gets in the high20's MPG
The 2009 Chevrolet Impala runs on flex-fuel (FFV).
The 2010 Chevrolet Impala runs on flex-fuel (FFV).
The 2006 Chevrolet Impala runs on flex-fuel (FFV).
The 2008 Chevrolet Impala runs on flex-fuel (unleaded/E85).
The 2011 Chevrolet Impala runs on flex-fuel (unleaded/E85).
The 2012 Chevrolet Impala runs on flex-fuel (unleaded/E85).
The 2013 Chevrolet Impala runs on flex-fuel (unleaded/E85).
You cannot burn E85 in a vehicle that is not Flex Fuel. I do not think your Trailblazer is Flex Fuel. If it is it will have a yellow gas cap, and a sticker saying Flex Fuel. If you have any doubts look in your owner's manual or call your GM dealer and provide your VIN#. They can verify if it is Flex Fuel.
On a 2007 Ford Taurus : The 3.0 liter " Vulcan " V6 engine ( or the flex fuel version ) takes the ( Motorcraft FL-400-S engine oil filter ) according to the Owner Guide and
Ford Flex was created in 2007.