milage drop

[notron46]

my 05, 3500 4x4, 6spd, 373 gears, slr, diesel, was consistantley getting 22/23 mpg highway dirving at 60/65 mph. now for the last 4 fillups, at different stations my mpg has dropped to 18/19. any help would be great.

 

[LandShark]

Where do you live??? Winter diesel?

 

[mfburns]

That's a 16-20% drop, thats too much for winter fuel alone. I have only dropped about 1 MPG during the winters here in PA. Any other indicators?

 

[JR2]

Here in AK I go from 15-18 MPG in the summer to 10-12mpg in the winter, maybe they finally got around to giving you the really crappy winter fuel. .

 

[notron46]

I'm down here in sunny Florida, No other symptoms, runs great otherwise.

 

[RRees]

Silly question: Brakes adding resistance.



Is your parking brake dragging?



Check air filter?

 

[ToolManTimTaylor]

Moved here from the 911 forum. For more exposure.

 

[JimB1]

Suspect air supply.



Check filter minder for partial clogged air filter indication.



Check boost hose clamps for possible boost leaks.

 

[notron46]

I have a well maintianed K/N filter and i use Lucas fuel treatment.

 

[notron46]

I have a well maintianed K/N filter and i use Lucas fuel treatment. I have checked the clamps on the intake and they seem ok.

 

[Jorge]

MPG drop

In October of 2006, the regulations that were mandated by the EPA went into effect. Most of the lubricity is gone in diesel fuel. We who own both large and small diesels are beginning to see fuel system failure due to the newer fuel specs. It is my feeling that you must replace diesel fuel lubricity with a combination of used motor oil, cetane boost and acetone. This has had a dramatic effect on engine performance.



My medium diesel is my 1996 Dodge DRW extcab auto with 242K on the clock. I think I have 180 HP. I really noticed the drop in cetane(39-40). I try to get the cetane to about 44-46. My fuel pump is the only lubricated pump that Cummins puts in the Dodge, however I still lubricate the fuel.

 

[notron46]

mpg drop

does it have to be used oil? and how much?

 

[CStringer]

NEVER put used oil in your fuel... your asking for problems. why would you want to dump those metal particles that you pulled OUT of your engine, back into your fuel supply to go thru your lp, and hp pump... . ?

older trucks you can prolly get away w/ that easier. . not the cr motors

i would give this a shot and see how it does.
STANADYNE - PERFORMANCE FORMULA - DIESEL FUEL ADDITIVE-Dodge Cummins and Ford Power Stroke Diesel Truck Accessories - Geno's Garage

or if thats too pricey, at least give Power Service a shot... the White bottle is for winter i believe...

and try cleanin you air filter as others have suggested...

another ?... how long since you changed your fuel filter?

 

[Jack in Alaska]

I keep my truck in Arizona in the winter... ... ... ..... no winter fuel problems... .
I seriously question the 22/23 mpg claim.

 

[burnin oil]

Run the valves. I did my o4. 5 at around 40k and many of them were out of spec. That netted me a few MPG. I can see his MPG claims. I have gotten mid 24 hand calced a few times although it is usually 19-20 running empty and not in town with a stock tune.

 

[CStringer]

not necessarily... where do you get fuel from? truck stops are going to have at least sum sort of winter blend to keep the otr guys happy. otherwise, fill up in az and head east and your fuel gels. so, it could still be winter fuel.



hold old is your fuel filter? whats your air filter look like? how long since youve given it a good ol fashiond "italian tune-up" ??



things to consider

 

[Jorge]

I run the used oil through my fuel as it has been through two bypass filters. It may contain some metal however the secondary and primary fuel filter is there to preclude that. My ratio's are 32 oz of each(Oil,Cetane boost and PURE acetone)

 

[notron46]

mpg drop

My fuel filter gets changed every 5k along with the oil filter, use rotella syn. I check my milage with a calculator. fill up, drive highway a few hundred miles and fill up again. sometimes at truck stops sometines not. only fill it till it clicks off. could it be something with one of the sencers sending a wrong signal?