Nissan Repair: pathfinder (2005) window rattle and decreased gas mileage, gas mileage, quality gas

Question
Bought new 1 year ago and have brought to dealer X2, first time told that they couldn't find the rattle in the driver's window. Second time told that it was normal to rattle (has "jumped" out of the track twice),  Taking to dealer again, they are going to demonstrate on new car?
Also noticed 4-5 MPG decrease in one year.  Is this normal?  Thank You.

Answer
Al,

That would be interesting to see the dealer explain that the window jumping out of the track would be normal...  Be sure to use quality gas as the injectors do not like discount gas.  The filter for the car is in the tank and it is really only a sock so the debris goes straight to the injectors.  That would be my thinking on the fuel economy.  Run a couple of tanks of super through the tank along with STP or other type of gas treatment.  Also, make sure the tires are inflated properly.