I have a MGM 1998. It has 269,198 miles on it. These cars are built to last. I am going for 300,000 miles. I have had very few problems

 

Florida has been using E-10 in all its gasoline for a few months now and my mileage in 05 Crown Victoria has dropped close to 2 MPG. Doesn''t seem to run any different though.

My sister has a 07 Grand Marquis and that one did the same thing.

 

the more % in the fuel the less MPG''s you will get. it is cheaper gas but you lose MPG