How many times til you learn?

Just had my yearly lesson on fuel filters. In the summer fuel filters mostly last an entire oil change, in the winter they rarely make it. You can tell by the milage dropping. My milage quickly went in the crapper for the last 2,000 miles and just today I rememberd to check the filter, and sure enough it was full. Changed the filter and everything is good again. This happens every winter, I keep a spare in the truck just in case. You would think I would remember by now, but not so. Probly wasted a couple hundred dollars in fuel for a $20 filter. Oh well, lesson learned, again. Maybe next year I'll remember before I waste a bunch of fuel.

I guess I'm lucky. I don't replace them on anything. Not that I wouldn't but don't seem to have to. I use a final water absorbing filter on my diesel pump and buy my gasoline from reputable, high volume dealers.

How many miles on oil these days???

We used to go about 15k many years ago, fuel filters always made it.

I'm assuming this is in your Volvo semi truck, right?
What causes the fuel filter to 'go bad'? What does it get full of?

I bet you fill up all over in god knows where and are bound to get junky fuel.
Back in the days when I had a GM diesel truck with the 6.2 (junk)I would fill up at local stations. My filter had a drain on it and I'd drain off a lot of goo. Finally put tank in at house with filter on it and no more goo in my truck filter.

I always wondered if the filter on my barrel did much good. This thread proves it. Actually if I am replacing filters on my diesals I know there is a problem in the chain of my fuel supply and start looking.

jt

What does a dirty filter have to do with mileage? All the miles I drove in almost 30 years I always had a new filter in the side box. More than once in below zero temps I had to change the filter, but never suspected a loss of mileage.

on the new trucks they use a common rail fuel injection. when the flow and pressure go down so does the fuel going into the injectors. He probably has a fleetguard fuel filter, as it gets dirty the fuel rises in the glass bowl on top.

I'm not sure why, but I ran empty from Denver to Kansas City and a light load from there to Viginia and should have gotten 8.5+mpg, but got 7.1. I supose the truck compensates for low pressure by increasing volume. Never notice a drop in power tho which would make more sense to me.

You have to take into account how much I drive, 20,000 miles on an oil change is 500 +/- engine hours. So that is about where I would expect trouble with tractor filters too. Truckstop pumps also have a filter on them like what you have, but theymust not be too fine because they let stuff through.

Just regular fuel stuff, I think when it's cold there is more wax build up or water.

I change at 20,000 miles which is in the 500 hours range, Volvo recomends 25,000 or 800 hrs which ever
is first. It's a little different now since I don't idle much, so I probly get less hours in 20k miles
than older trucks that idled a lot got in 15k.

Crappy BIO and cold weather do not mix. It is worse with me because I don't use my truck that much. We have certain stations that we don't use in the winter. Caseys now sell BIO free diesel in our area in central IL.

Wax... interesting. I was thinking dirt dust and grime. I don't know much about fuels, I'll have to read up on diesel and how it behaves.

(quoted from post at 10:37:39 11/29/16) I'm assuming this is in your Volvo semi truck, right?
What causes the fuel filter to 'go bad'? What does it get full of?

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"Clean" diesel in the US is ISO 4406:1999 18/16/13 which means there are between 1300-2500 <4 um particles per mL of fluid, 320-640 4-6um particles per mL, and 40-80 6-14 um particles per mL. The filtration system on a modern T4 diesel needs to take that 18/16/13 fuel and clean it to ISO 13/11/7 to get adequate hpfp (on common rail) and injector life. ISO 13/11/7 is 40-80 <4 um particles, 10-20 4-6 um particles, and .64-1.3 um 6-14um particles. These particles may be wax, silica, organics, etc. Your eyes can't see them but they plug filters over time. The switch from summer blend to winter blend releases a lot of crud in all the equipment from the refinery though the pipelines, bulk tanks, tank trucks, and vehicle fuel tanks so fuel is "dirtier" in the early winter and filters don't last as long.

I've seen worldwide fuel quality studies and the US is pretty good in terms of cleanliness but I have caught samples from bulk tanks in mines in WY with fuel that was ISO 25/23/20 (160,000-320,000 4um particles per mL). We designed filtration systems to get half filter life (250 hrs) at ISO 24/21/19 and in most cases would last much longer than 500 hrs on good fuel in US.

(quoted from post at 15:12:44 11/29/16) You have to take into account how much I drive, 20,000 miles on an oil change is 500 +/- engine hours. So that is about where I would expect trouble with tractor filters too. Truckstop pumps also have a filter on them like what you have, but theymust not be too fine because they let stuff through.

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the filters you see on pumps is pressure side filter and generally do poorly in terms of efficiency. Beta is the typical term used for filter efficiency. A beta of 2 means that the filter is only catching half the particles of a given size. Pressure side filters with cellulose media typically have a beta of 3-4. If they would have put the filter on the suction side it's have a beta of at least 10 but very typically closer to 100 or even maybe 500. Dirty filters are more efficient but at the expense of pressure drop which is where your mileage drops are coming from. Hydraulic systems have filters typically downstream of all the pumps/valves, actuators and on the return to tank side.

You have to remember Jon probably is in a different state every time he has to fuel up and probbly has never been to any of the stations or pumps to know how they do things. And then possibly a summer blend and next winter blend and back to summer so he will never end up with either a summer or a winter full blend. I know nothing about diesel fuel but know that mixing at every fill up will never get fully one thing or the other. And the southern states should have a different time to switch from summer to winter than the northern states that he is from. Not like you buying fuel for your farm tractor.

Jon , drop in fuel mileage can also be due to wind and fuel cetain rating and summer fuel and winter fuel. That Dodge of mine is as fussy as the War Dept. when it comes to fuel , then ya add in the wind drag of that box i have on the back . I do not normally travel that far with my one ton but the one time i did take it to Mo. a few years back i had real strong head winds all the way out there and i was only getting 10.5 MPG . I knew i was working the snot out of it as to how hard i had to lean on the go pedal and the fact that the temp gauge was running 195 to 200 at hyway speeds . Same thing when i had to move my daughter from Cinnci to Toledo i had a head wind heading down to Cinnci and trying to run 70-75 down 71 i was almost on the floor and fuel mileage plum sucked heading into the wind . Now on a big truck when i had my coal bucket if you ran into the wind with the bucket empty and no tarp it would pull as hard as 30 ton in high winds , if you popped the gate it would stgand straight out going down the road at highway speed , It pulled a lot better but the cops did not like it . Now you add in Bows and a tarp with a rope down the center of the bows you never felt the wind .