time to change fuel filters alert. switch to e85 kicked up sediment

[thisisntjared]

i dont know how true this is but my buddy with a chevy z71 or whatever it is(big truck) went from 12 to 8mpg. he changed his fuel filter almost exactly one year ago and when he changed it last week there was tar in the filter. like sludge tar and he said it smelled horrible like burnt something. so he cleaned out his entire fuel system and got new plugs and hes back to 12mpg.

he talked to his friend who is a mechanic and his friend said recently he has had a lot of cars with the same problem and attributes it to the fuel switch as the refineries scrub down the tanks or whatever and kick up all the sediments and ship that out. the sediments are being stirred up in the refineries and in the gas station tanks themselves. again this is all hearsay, but it seems legit to me.

i have not changed my own fuel filter yet, but i wanted to know if anyone else has seen anything like this. i did experience quite a dip in fe recently, but then again i have been driving a lot less and going to the track a lot more.