Fuel Filters and MPG

stoutdog · **Posted:** Thu Apr 15, 2010 9:54 pm

Quick question: I'm on my usual monthly trip to Flagstaff, which is about my most consistent drive for calculating variances in mpg against speeds and fuels. Over the past few months, I've found that the trip up I-17 from Phx and back (a 6,000 ft elevation change, each way) nets me 31-32mpg @ 60mph and 28-29mpg @ 75mph, running both dino fuel and B25.

This time, however, has been different. I'm running B80 (after running B99 two tanks ago), so I'm expecting some loss in mpg. I've been told 2-3mpg, at most. However, when I arrived in Flag yesterday my EVIC read 28! As a point of comparison, I check my EVIC at the exact same spot on the highway every trip and at 60mph it would normally read 34 and at 75mph it would normally read 31-32. I know, I know, only a fill up will show me my true mpg, but all indicators are pointing to something in the realm of 26 or so... About 6mpg less than what I would get at the same speed prior to this trip!

So, my question: Is it possible for a fuel filter to get progressively clogged with crud from the tank/lines? I have not noticed any significant drop in performance, or the obvious "oh dang, my filter is completely clogged and she's dead in the water" syndrome. But could it be clogged enough to be hurting my mpg without impacting performance/drivability?

Thanks.

onthehunt · **Posted:** Thu Apr 15, 2010 11:04 pm

Filter condition has no impact on mpg.

stoutdog · **Posted:** Sat Apr 17, 2010 12:09 am

Seems you were right... My EVIC was just reading scarily low, as B80 netted me about 3mpg less than regular diesel would do, which is to be expected. Thanks.

Cowpie1 · **Posted:** Sun Apr 18, 2010 10:26 pm

onthehunt wrote:

Filter condition has no impact on mpg.

Try telling that to semi truck owners and see what kind of a response you get. Let me know, so I can watch! :ROTFL:

Fuel Filters and MPG

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