I've got a little over 100,000 miles on my 03' JCW MCS. I've thought about changing the fuel filter for a while now, but have just been putting it off. Everything runs fine, and I haven't been having any issues. How do I know when it's really time to change it? Will the motor start running funny? Or should I just change it now and be done with it?

 

Why wait 'til you're somewhere in the boonies, it's below freezing and pitch dark out when your MINI starts coughing and sputtering because the fuel filter just couldn't stand all the crud you picked up from that last gas stop?

 

For most....when you feel like it....
If you pay attention to the feel in higher end, fuel thirsty times, you might feel a bit...or might even get a code....
But for most...folks just do it cause they can....
One bit of a tip...
Fuel in pre-ethonol days would leave a varnish on tanks....when the ethanol came out...lots of filters were clogged with this tank residue that the e10 dissolved....both in gas stations and in cars. Now...e10 works as a solvent....and if the stations stay clean...you are in pretty good shape...but IMO if you car is pre-middle of 2005, and you do not know if the filter was changed...it would not hurt....they always look dirty....but you might be able to look under the rear seat...and look for scratches.... See if it has been messed with.