Truck has been bad on fuel since new,done all the obvious,tire pressure,tranny re-learn to shift around 1800,new air filter...PPE tuner doesn't even help while pulling my trailer...10mpg as soon as I hook anything on the back.... Gotta something wrong from the factory.....any ideas?:mad:

truck now has 32,000 miles,best mileage was on the first tankfull......help?

Is your fuel mileage hand-calculated, or is the mpg according to your DIC? Is your truck a dually or a 3/4-ton? We might be able to help if we knew your truck configuration a little better - fill in your signature.

http://www.dieselplace.com/forum/showthread.php?t=234597
Did your last thread not answer your questions?
Is your odometer going backwards?:D

Fill out your sig, give us hand calculated numbers, tell us everything you have done to the truck.

stay out the dang skinny-pedal!

stay out the dang skinny-pedal!
I only give it enough throttle to get moving...no smoke,still sucks fuel-what's wrong with it?

How big is the trailer? by this I mean how tall is it above your truck? What mileage are you getting while your not towing? Hand calculated.

I had a 23' TT and some days I only got 10-11.

check your mass air flow meter as well. mine was off on the reading, not giving codes, and once changed my mileage came back up.

Real easy.

1) Fuel filter
2) EGR
3) Not enough miles
4) Work the truck really hard and then recheck mileage

I have a 33 foot TT and I have gotten as high as 13 mpg pulling it and as low as 8 pulling it.

BTW, where do you live, winter fuel sucks.

id LOVE to get 10mpg towing :lol:

I would love to get 10 miles to the gallon towing also. Not sure but my 05 was just as bad as my 06 for fuel mileage.

All I gotta say is deal with it I must have gotten one of those crappy fuel mileaged trucks too, I have never seen 14mpg with this truck since it was new, and thats keeping it under 2000rpm's with the predator turned to 0 hp and the edge on level 1 (30 hp). Before anybody says anything about the oversize tires, I was getting this for the first 3,000 miles on it with the 245's, it's been to the dealer twice now for it and they said there is nothing they can do about it, so now I just drive my other truck cause $.45 a mile in the duramax is just to expensive anymore

Wind resistance and towing speed can be your problem. When towing wind resistance is much more important than weight. I get 20 to 22 MPG depending on speed and conditions on the highway not towing. When I tow my 23' travel trailer the mileage goes way down to 10 to 14! Just the way it is! Wind resistance!

All I gotta say is deal with it I must have gotten one of those crappy fuel mileaged trucks too, I have never seen 14mpg with this truck since it was new, and thats keeping it under 2000rpm's with the predator turned to 0 hp and the edge on level 1 (30 hp). Before anybody says anything about the oversize tires, I was getting this for the first 3,000 miles on it with the 245's, it's been to the dealer twice now for it and they said there is nothing they can do about it, so now I just drive my other truck cause $.45 a mile in the duramax is just to expensive anymore

Your truck wasn't even broken in at 3,000 miles. How many miles do you have now?

I'll jump in here too.

My truck is a 2006 crew cab 4wd LBZ. Has 285's on 16x8 MM's. When I hook my 7x16 enclosed trailer I get 9-10mpg Hand calculated. Empty I get 13-14mpg. This is all hand calculated. When I had 245's I only got a little over 10 at best hand calculated.

My trailer is loaded with mowing stuff, guessing weight would be 5-6k lbs loaded. The trailer is 6' tall. I drive very easy trying to save fuel as much as possible.

I had decided to just live with it, but if there is something to check...that would be great.

Never had any codes, no mods. Fuel filter changed every 5-7500 miles. Oil 15W-40 Rotella every 3-4k. Truck has 17k miles.

Thanks

I set the cruise at 65 (which is ohhh so painfully slow) and did a 200 mile round trip and the DIC said 20.6 when I got home. Its been accurate the last few times I checked it by hand. Going 75-80 brings it down into the 16 range.

Your truck wasn't even broken in at 3,000 miles. How many miles do you have now?

About 16,000 miles

Have you had the tranny and engine flashed at the dealer????
My milage went down drastically recently and I took it into the dealer.. I went from mid 14's in town to around 11mpg. The dealer flashed the tranny for a sudder I was getting then 100 miles later still poor milage and now a check engine light!!!
When I took it back to the dealer I talked with the Tech personnally and found out that at the previous (before tranny flash) service they did a flash on the ecm per GM. The tech let me read the info on the flash and it clearly stated that it may reduce millage... The tech was really cool and went through all the flashes that were available from GM for my truck and found the one we thought would help the best and did the same for the tranny...
Now my millage is up to 16.2 city and the tranny feels like it is shiftting a little firmer.

Have you had the tranny and engine flashed at the dealer????
My milage went down drastically recently and I took it into the dealer.. I went from mid 14's in town to around 11mpg. The dealer flashed the tranny for a sudder I was getting then 100 miles later still poor milage and now a check engine light!!!
When I took it back to the dealer I talked with the Tech personnally and found out that at the previous (before tranny flash) service they did a flash on the ecm per GM. The tech let me read the info on the flash and it clearly stated that it may reduce millage... The tech was really cool and went through all the flashes that were available from GM for my truck and found the one we thought would help the best and did the same for the tranny...
Now my millage is up to 16.2 city and the tranny feels like it is shiftting a little firmer.

That's more like it... On big trucks you can pick from assortment of maps for different applications,and I know of 2 local Cummins owners that did and got better mileage,se why can't we? This thing still gets worse mileage than my old 5.3 did and that is sad...Where did the technology go...?

check your mass air flow meter as well. mine was off on the reading, not giving codes, and once changed my mileage came back up.


How can I check the mass air flow meter?

rmat-2500hd, i have a 2001 duramax. dealer reflashed for a FPRV replacement , my mileage dropped from 17 mpg city to 12 -14 mpg city, dealer says they cant go back on a reflash and remove it. what are the chances of you giving the name of your dealer and any other info you may have . this really sucks.