what do you guys think can be done for poor fuel mileage? i guess i'm not real comfortable taking it to my dealer because i know they will tell me it's alright. that's just the way my local dealer is and there is'nt anybody in my area that know's diesels that well. any input would help. towing it made 8.8 and empty it made 14.5

You could start by removing the cat, changing to synthetics all around. Anything further then that we are going to have to wait for the General. I have talked to my service manager about this a few times and he say that GM is aware that there is a problem and he seems to think that they are working on solving it. Time will tell.

That is about what I'm getting. 8.1 pulling 13K and 13.9 empty. That mileage convinced my dad that the 8.1L gasser is the way to go.

I have 2700 miles on my 04.5 LLY Auto.I Have been towing up and back through NewEngland a good mix of flat and steep grades.Pulling 8000lbs at an 72 Mph average Im averaging 12.2mpg.When pulling an empty 2200lb trailer 14.7. Im averaging 16.2 mpg city/highway on my daily driving with just the truck and Im pretty heavy footed. This truck was mfg in early June and delivered 3 weeks ago after a long 12 week wait. possibally a different flash could be the reason for the different Mpg's?

I took a 700 mile trip to the mountains this weekend and according to the trip odometer, my fuel average was 20 MPG. I was not towing my rig. When I refilled several times just to keep topped off, my math agreed with the system MPG computer. My vehicle was manufactured in May 04 and is 2WD.

We just completed a 2 week trip towing a 25 foot travel trailer (6000 lbs) putting on about 3500 miles. Our worst day towing was 9.3 (with a strong head wind) and the best was 11.3, with an average of about 10.5. We went to Montana and Idaho so this was a mix of flat and mountain driving both on interstate and two lane roads.

Without the trailer we are getting between 16 and 19 depending on terrian and speed. The best was a tank in the mountains with a speed of only about 50 MPH which we got over 19 on. For most interstate driving empty we get about 16 and in town about 14.

We have about 12.4K on the truck now and love it. It is great to be able to pass with a trailer on hills both on the interstate and on 2 lane roads. My wife (who does all the driving) was very pleased with the power and performance of the truck.

There is a noticiable improvement of mileage if you keep the speed below 60 or so. The back roads are where we see our best mileage at.

The miallage seemed to pick up after about 7K. I can only hope that we keep seeing a little bit of an improvment as we finsh the break in period.

Hope this give some of you some hope.

John

I am very happy with my milagehttp://www.dieselplace.com/forum/smileys/HiHi.gif. I have not done any towing yet as my truck is mostly a commuter. I am getting around 17.5 mpg city, and 24 highway. I have friends with their Toyotas grimmacing that they can not do any better. My truck far and away passes the milage of my wife's Suburban w/ 6.0l gasser (11/15), which was one of the primary purchasing criteria.


My manufacture date was February according to the tag.


http://www.dieselplace.com/forum/smileys/Hug.gif Love my truck http://www.dieselplace.com/forum/smileys/Hug.gif

last trip to northwest ontario 3 people all our gear no trailer hwy 70 -75 . before trip installed amsoil air filter last trip to dakota's was 18.7 this trip first tank 18.9 second fill was 19.38 from ontario back to kc average was 19.7 now have 14k + miles the more miles the better it seems to run. air temps were low to what we have had also.