poor fuel milage

[SLinse]

I'm having some issues with my truck. I have noticed a big decrease in fuel economy. The last to tanks have been around 14. 7 hand calculated. I was geting 19 and 20. My truck also has a back fire, but only while I'm running my EZ. I'm wondering if a bad injector would cause this?? Any ideas?

 

[bulabula]

Is it throwing any new codes? Was the 19 and 20 (those are pretty good figures) also hand calculated? They didn't change the fuel blend up there for the winter yet, did they?

 

[SLinse]

ya those were also by hand. I'm sure they haven't switched yet. even last winter when I would let the truck idle a ton I would get 13-14.

 

[nfox]

Fuel Mileage

My friends 2004 3500 single rear wheel truck was getting 19 to 20 empty on the highway and it has dropped back to 15 to 16 and his power is going away slowly and the dealership scanned it and said everything is alright.

 

[SLinse]

I did find out that they switche to winter blend fuel already. That must be the problem???

 

[GOTSOOT]

Slinse: Not a good idea to let `er IDLE A TON!

 

[SLinse]

at -50 or -60 below, sometimes you just don't have any other options!

 

[JohnSS]

Mine too!

That sounds basically like mine. It started out around 18. 1 mpg and is now down to 15. 5 or so. Totally stock with around 19k on it now.

I have noticed blackened rear panel above the exhaust, and also when I punch it hard a lot of gray smoke is coming out the exhaust. Not sure if that is normal or not.

 

[Bob4x4]

I would check lift pump pressure... ..... and rail pressure



Bob

 

[KBertetto]

SLinse,

I just filled up at the Holiday at the New Seward Overpass on Abbot/Dimond Rd. The have not switched to winter blend as of yet. I know your out in Wasilla, but if your in that part of Anchorage get a fill there.



Bert

 

[dnitzel]

I have NEVER gotten more than 16 mpg empty, calculated, traveling all highway, calm day, flat land, traveling 60 to 65 mph. I consistently get 10-11 pulling my camper at 60-65. Just turned 25k. Is it the 285 tires? Or are people just hyping up the mileage a bit? I still like the truck, and will still like it even when diesel goes up another 50 cents this winter!