Last post on Sep 27, 2013 at 11:50 AM
You are in the Diesels
What is this discussion about?
Chevrolet Silverado 2500HD, Chevrolet Silverado 3500, GMC Sierra 2500HD, GMC Sierra 3500, Diesel, Fuel Efficiency (MPG), Truck
#83 of 623 Re: DURAMAX FUEL MILEAGE [blackmax]
Sep 13, 2005 (9:25 pm)
I have a 2005 GMC Sierra, 2500HD crew cab, 4x4 w/ D/max and the mighty Allison trans.. I've owned a new duramax every year since '01. I've loved them all. Even through all the injector problems. I've always gotten 15-20 mpg no matter what I pulled or how I drove. I now get 11 mpg and I try to keep my foot out of it. I've been looking at the new Preditor chip for better economy and power. I see about $500 and it plugs before the turbo and before computor.
Anyone have experience with it?
#84 of 623 Re: DURAMAX FUEL MILEAGE [fxwg82]
Sep 13, 2005 (9:30 pm)
Oh, I forgot. I put Michlin 285x75x16s on it and the rub in the standard left front wheel well was there. I Jacked the torsion bars a hair as I've done with all my Duramaxes. It works.
On this rig I also put removed the muffler and installed a split, dual exhaust w/5" chrome tubes.
#85 of 623 Re: HELP! New Diesel Owner on MPG [sleadhead44]
Sep 14, 2005 (3:37 am)
That is Very Low mileage. I have 2003 2500HD Duramax with the 5 speed automatic and tow a Potomac 35 foot 13,400 lb 5th wheel. My wife and I take several trips a year to the mountains and traveling down Rt 81 through Virginia with the cruise control set at 70-72 mph (you have to in Virginia or the big rigs will blow you off the road); I consistently get 15 mpg on the flat country and 12-14 in the Hills.
Do you have the Alison 5 speed Automatic Transmission?
Are you using the cruise control? If not you could be a gas peddle thumper!
Are you using the tow button? The only time I use the two button is when coming down out of the hills to reduce using my breaks - if you always use the tow button it will take 5th gear out of play - that would account for you lousy mileage.
Lastly if all else fails use your warrantee and get GM to check it out.
#86 of 623 Re: HELP! New Diesel Owner on MPG [benr]
Sep 16, 2005 (6:54 am)
Forgot to mention my 03 is a crew cab short box.
and what is all this about injector problems? when does this happen? I'm headed to this hills this afternoon and will roll over 30K miles this trip please don't tell me I have something bad to look forward too. Also when not towing my milage holds 18-21MPG to and from work and around town in the meto area of DC.
also a news flash that I just came accros this morning - here I'll paste it:
New August 25th: GM has announced a voluntary customer satisfaction program (#05546) for current owners of Duramax diesel equipped vehicles. In a letter dated August 2005, current registered owners were informed that they are eligible for one free fuel filter replacement, and GM has instructed their dealer network to perform this service free of charge through September 30, 2006. Please contact your local dealer to learn more about this free offer, or call 1-888-996-9463 if you need more information.
Think I'll take advantage of this one, I'll need an oil change when I get back anyway.
#87 of 623 Re: DURAMAX FUEL MILEAGE [fxwg82]
Sep 19, 2005 (9:42 am)
I am getting a set of 285/75/16's put on this Friday. What do I need to do to dial up the Torsion bar? Also I am told I will need to get the dealer to calibrate the speedo. Is this correct?
I would love any help I can get here. I just don't like the look of the 245's. Also was always getting stuck in the back yard if it rained. Figured that the wider tire may make the truck "float" a little better in the mud.
Any help is appreciated.
#88 of 623 Re: DURAMAX FUEL MILEAGE [victorycruiser]
Sep 19, 2005 (12:25 pm)
When I put on the 285's I found my speedo was off about 5 mph. I went to the dealer to recalibrate my speedometer and the dealership told me that Chevy will not recalibrate the speedo on duramax trucks. Stupid huh? But I seen a recalibration chip by superlift for about $190. In case your tire shop doesn't tell you you need to get an alignment after raising the torsion bars.
#89 of 623 Re: DURAMAX FUEL MILEAGE [victorycruiser]
Sep 20, 2005 (8:20 am)
The 285s will definitly fill the wheel wells better and make the truck look better. Everytime I've put 285s on one of my duramaxes, the right front will rub. If ya put splash gaurds on it's worse. By raising the front end with torsion bars is easy to do by reputable alighnment shop and a slight alighnment is needed. It will also rais the front end, leveling the truck.
As for the speedometer: A difference of 2-3 mph faster than it shows. Not a big deal for me and I've never worried about it or inquired about an adjustment.
#90 of 623 Re: Real MPG numbers [06lly]
Sep 22, 2005 (2:13 pm)
Is the LLY the new Duramax that is coming out with the 06 trucks? I am thinking of waiting for the new engine but it is not widely available.
#91 of 623 New 2006 Duramax mileage
Sep 22, 2005 (2:21 pm)
Is anyone driving the NEW 2006 Duramax diesel yet? I'm thinking of ordering one with the new engine and am curious regarding fuel mileage in the 2500 truck.
#92 of 623 Re: New 2006 Duramax mileage [jmccormick1]
by KCRam@Edmunds HOST
Sep 22, 2005 (5:00 pm)
According to GM's press release, the new higher-output (360/650) Dmax won't be available before November.
kcram - Pickups Host