has anyone had their truck fuel milage drop really bad , mind has droped from 18 to 12 to 13 mpg can they gt stuck in regen cycle, still runs great,

 

I was getting around 17, then 16, now 15.5. Bought it new in December, cc lariat long bed with 3.55 and 20's. I thought at first it was winter fuel, then maybe it had something to do with the oil change, but I changed oil and topped of def, rotated tires. Was using power service, them tried pm 22. I haven't seen the drop you have, but I hope mine stops going down. I haven't towed yet and drive about 500+ miles a week.

 

I was geting about 22 and now it seems it is 16 I have 20s and 355 i use pm22 and skip a tank once in a while maybe just heavy foot p.s i have 2100 miles so is still learning

 

mind had 17 tires an i put 20s on it and i got 331 gears , i know that changing wheels an tires should not drop 5 to 6 mpg . sometimes when my truck is ildling the fuel filter under the hood starts makeing a loud humming noise , and it will do that for a day or so an you can hear it real good driving dn the road.

 

what is pm22 ,bought this truck private an dont know about it very much he filled the DEF up at ford garage when my son picked it up.

 

pm 22 is a diesel fuel additive from Ford. Basically an octane booster and lubricant. If you haven't noticed there is a lot of talk on here about the high pressure fuel pump failure, and an additive is a possible preventative step. I don't know that I buy into it, but it is fairly cheap and I don't see what it hurts.

 

what about fuel filter hum has anyone ever had that ,it is on the outlet side of top fuel filter.

 

My MPG was better when new. It has not improved much with age.
Then a few weeks ago I added larger tires and that eliminated the 15 number from ever showing up again.
I was expecting a loss of 1 MPG but it's closer to a loss of 2 MPG (1.7 ish).
Oh well, I didn't buy this truck to run like a hybrid.

Ken, that large of a drop though and something must be wrong.
Dirty fuel filters (easy enough to replace) or something else is wrong.

 

I am not quite sure what to really make of the fuel mileage. My driving is mostly country roads around 60mph, but I do a fair amount of in-town driving as well as highway driving.

For the first couple months I had my truck the mileage was around 18 average (overall). Then sometime through last fall and winter it went down to just over 17.

My trip B is never re-set, its run the totals since the truck was fresh off the semi. I reset my trip A and fuel economy with every tank.

Daily driving I am around 17mpg. If I do more in-town driving (and don't get up on the highway for a few hundred miles) the mileage will be below 17. If I run a lot of highway and the weather is decent (light wind if any) I can get 18.5+. I've made a 100 mile trip headed west and south a bit and made out at 20mpg at the end of it with a fresh tank just before I hit the highway (VERY light on the throttle and baby'ing it the whole time, still running 70 or so on the highway). That having been said, the exact same route in a head wind took me to 14 mpg.

I started today at 16.7mpg and finished at 17.3mpg - and all I drove was my 50 mile round trip commute, with a bit less than 1/4 tank burned since I filled up.

There are far too many variables to fuel mileage to make much sense of it.

 

Change your air filters every 10k forget what the manual says. Mine went from 13 back up to 17 when I replaced it.

 

Cabindoc, is your pop out filter minder on the filter showing it's filling up, restriction should show on the air filter mounted gauge.

 

What will the B20 do to mileage? Same decrease as the E85 in a gas engine?

Recently my NOX sensor went out and the mileage went to 13 on the highway, unloaded @ 65 mph with the power stroke fuel treatment. After the fix the mileage returned to 17-18 mpg

 

Did you set your PCM to the new tire size? It's a dealer mod...

As long as you went to a R20 tire that is still OEM size...IE: going to a 35" r20 tire will cause the drop.


biz

 

Just a thought on the milage, have any of you that had a reall sudden drop changed your fuel filters? Just a thought.

I have to change mine at evey oil change to try to keep things flowing well.

My truck when it was new would get 20 mpg on the hwy, now it seems to like 19-17 mpg. During the winter the best I can get around town is 13.5-14, summer on the other hand it seems to come back up to 15-16 depending on how I drive. I have 36,000 something on it now.

 

Im going to bump this I just changed my fuel filters for the first time and yes the bottom ome is tight yes I changed the gasket the yellow drain **** is tight, but I get a loud humm from the top filter and I cant figure out why. I bought the filter from the ford dealer and I have no idea how to get it to stop.. I actually drained the bottom one took it all off and put it back on cycled the key 6 times took the 2 hoses off the top one put them back on made sure they were as far forward as they can go and they were attatched right. can anyone help/