Changed the fuel filter on my 1.4 tsi on Saturday, easy enough to do once I'd got the right part. Noticed a definite improvement on idle, quicker startup and smoothness. Wouldn't say its quicker but definitely smoother. Mine had done 60k with no record of a change before. Always use v power (but only got the car at 54k) not noticed any mpg benefit but happy with the new smoothness :) if its not been changed before and you're at 60k+ you havnt got much to lose as its pretty cheap and easy to do :)