Ok guys, I filled up today and calculated my fuel mileage and it was 11.4. Normally its lke 12.5-13. I did add 360 lbs of sand in the back under my tonneau cover but why is my mileage so low? I have cleaned my IAT, changed the fuel filter, and reset the APPS and no improvement. My fuel pressure was good a few months ago. I am really getting sick and tired of paying all this when I should have better mileage. Anyone have any other ideas?

 

since you are in New York, I would attribute your mileage loss to winter blend fuel. There is a product at walmart called Powerservice that advertises to impove mileage while usinge winter blend.

with that said, I am also experiencing fuel mileage loss. My question is: In coastal Texas, do the pump stations switch to winter blend? I would think not becuase we have mild winters around here.

 

Yeah I have tried Power Service before with no luck in improvement. I'm lost for ideas.

 

This must be in town, stop and go mileage. If that is the case, you are just a bit low. I would run some diesel injector cleaner through the system and see if that helps. Dirty or burned injectors really knock the mileage in a hurry. Winter fuel will also take it down a bit, if you can find some non-detergent 30 wt oil (do not use detergent oils), slip a couple quarts in the fuel tank, fill it with diesel, and your mileage will come back if it is just the fuel that is the problem.

 

Shell X100 straight 30 wt oil has the lowest ash content.

Dude, I can understand why 11.4 MPG would set you off, but why didn't 12.5? You must have other causes besides winter fuel. Heavy foot?

 

I do have a mildly heavy foot but I dont see how it would make it that low. Since I just fueled up I am going to not mash the throttle and just take it easy. Now I downshift to save my brakes and I let it idle quite a bit. Could that be the problem?

 

Down shifting increases RPM's aabove 1800. This in turn will bring down fuel economy...Idling for long periods will cut mileage as well....850 rpm and tires going 0 rpm = poor economy to boot....

Gary

 

Is this out of the norm for you for winter mileage? I see a 2-3 mpg drop instantly when the pumps change to winter blend.

 

Ok I will stop downshifting and not let it idle as much.

I have no idea what the winer mileage is because I bought the truck in May but why would have have just put the winter fuel in their pumps now? I fill up there a lot and just noticed the decrease. Dont you think here in NY they would put the winter fuel in sooner than early december?

Would replacing my speed sensor help? I dont know if I have all the power I am supposed to because I havent driven many other diesels that we'rent bombed so I have nothing to compare mine to. It seems ok and has some power, I figured it would have a little more though.....I DONT KNOW WHAT I'M TALKING ABOUT THOUGH!

 

Do these things have o2 sensors on them? In my Dakota, a bad o2 sensor is known for producing bad performance and fuel ecomomy. Just a thought.

Randy

 

I believe in a diesel its called an IAT sensor but I may be wrong. If I am, please correct me. Thanks for the help Ram04.

 

Do you still have the stock tire size? If not, your mileage can be off from bigger tires. I also have a very heavy foot and at times my commute isn't very far away resulting in the same #'s. > When a job brings me further away my mileage goes up to about 16. I also downshift a lot and let my truck idle. These are the things we must deal with with an auto. :'(

 

I have 285's

 

With my 285's, I figure correction at 10%. This would increase your MPG by 1.14.

 

ok thanks, I'll try that next time.