Common sense says there is no such thing as lifetime. Dirt gets trapped in there, that's what it's for. If your car is unmodified, you could probably go 10 years or 150K miles on that stock filter and never encounter a problem. If your car is chipped, realize that a higher demand is being placed on the fuel pump than Audi originally planned for. A clogged fuel filter in the system will only make it harder for the fuel pump to keep up. A drop in fuel pressure won't make your engine very happy. So again, common sense prevails. I'd be hesitant to go over 100K with a fuel filter on a modified car. It's a $10 part (admittedly a PITA to replace)...what's the point in delaying the replacement!

FOR SALE:
B5 A4/S4 STASIS TRACKSPORTS FOR SALE >> $1100!!!

Just arrived...
2005.5 A4 Avant 2.0T Quattro 6MT
APR 91/93/100 | APR Exhaust | 19" BBS RS-GT's | Carbonio | Partridge-in-a-pear-tree
Others:
>>2001 S4 sold
>>2000 A4 sold

*** September 11th, 2001 - Never Forget ***