New Fuel Filter Decreases MPG
 

I recently replaced the '89 300E fuel filter and have noticed a significant decrease in MPG (about 20 - 22 MPG pre OEM replacement and now @ 16-18 MPG). Any reasoning for this drop off would be appreciated....or should I be looking into some other system/part? Thank you.

I can't see why or how a new (or old) filter would have any effect on MPG.
I'd look somewhere else for the solution to the problem
JackD

First thing that comes to mind - Check for leaks.

:)

Ken300D