ok so this winter when I was idling a lot I figured that was why my mpg was around 8 or 10. Now its a little warmer so I dont let the truck idle in the mornings for more 4 or 5 minutes. After work I let it idle for 1 minute before driving. However my overhead which I reset at every refuel still is at 10 mpg which means its actually about 11.2 I use power service routinely. Is this typical for winter ULSD fuel or is there problems. Im thinking clogged fuel filter? soon as it gets in the balmy 40s here in a couple of weeks I'll be checking that.

 

Are you running #2 diesel?

Air up them tires

 

my tires I run 65 in the fronts and 70 in the rear. I checked them about 2 weeks ago

 

Auto/Manual tranny, 3:55/3:73/4:10 rearend ? Any mods ?

We need more info to help you, your sig. has "cool looking" descriptions but nut much what's underneath the hood.

 

3.55 in the rear automatic. stock no mods

 

Don't read the overhead, it lies !!!! Do a manual calculation, fill up, reset trip odometer, drive truck, refill and check how's your mpg.

3:55 auto at 8mpg/10mpg is very low, you should be getting 17/18mpg average