In the 2006.5-2010 Kia Optima, the fuel filter is INSIDE OF THE FUEL TANK, which must be drained & dropped in order to replace, first at the 30k mile interval.
I'm up here, at 43k+ miles, still starts and acclerates okay, but I suspect acceleration has decreased so slowly over time I've forgotten how quickly it used to jump off the line.
The service tech at the Valvoline where I get oil, etc done, said, "As long as you don't smell gas, and the car isn't always stalling, you're fine."
Do you *think* I should seek a second opinion? And what the F&~# is the fuel filter doing in there anyway?!