fuel

[MILD BILL]

Is anyone getting any decent fuel mi. out of their Duramax's?
What about upgrades?
Mild Bill

 

[Mad Maxx]

I do about 15-17 around Town and Low to Mid 20's on the Highway. All unloaded.

 

[BudTX]

I get 16-18 mpg on winter blend, but have a fairly modded truck. I see 19-20 on the highway with summer fuel, a light foot and a tow tune.

The best that I ever saw was 22 mpg hand calculated with a Predator programmer on 85 and LSD. Those low sulfur days are long gone, unfortunately.

 

[saratoga]

What do you consider to be decent?

I can brush the mid-high side of 22 doing 70 with the cruise set and driving like an old man. Average 15.xx-16.xx around town.

 

[Unit453]

17.5 around town and 22 at 70 and 23 at 65.

 

[btfarm]

15-17 winter and 18-20 summer. 90+% highway

 

[CtChevy427]

18.5 85% highway.

 

[BIGR]

The best ever was 22.8 MPG on flat ground. Was going to beat that in December but the winter blend must have killed the mileage because I only got about 21 or so on the same road and I drove like granny. I can't get much more than 18 MPG or so here around the house due to mountainous terrain.

 

[MILD BILL]

pip&pop

I do about 15-17 around Town and Low to Mid 20's on the Highway. All unloaded.

Yours seems to be more sinceable, what have you done to improve the mpg, and what would like or need to do?
mild bill

 

[MILD BILL]

OK What about the 3500's lets here from you guys.
MILD BILL

 

[Unit453]

Yours seems to be more sinceable, what have you done to improve the mpg, and what would like or need to do?
mild bill

You may not need to do anything. Some of these get great mileage right outta the box. Some dont. Most benefit with programmers, intakes or exhaust systems. The problem is that you never know what you're gonna get since none of these trucks are or ever have been the same.

I've been running a cat back and I recently took it off. I noticed absolutely zero performance or mileage gain from getting rid of it. I did however drop about 100 degrees EGT's.

 

[Mad Maxx]

Yours seems to be more sinceable, what have you done to improve the mpg, and what would like or need to do?
mild bill

All my Mods. are listed in my Sig. I just got rid of my PPE Tuner (Kept it on Level 6 all the Time) but that's what I used up until Last Week when I Sold it.

 

[socal2ks]

I get 16-18 mpg on winter blend, but have a fairly modded truck. I see 19-20 on the highway with summer fuel, a light foot and a tow tune.

The best that I ever saw was 22 mpg hand calculated with a Predator programmer on 85 and LSD. Those low sulfur days are long gone, unfortunately.

Bud when do they switch to summer blend here in Kansas?

I actually went buy a pump last night that had LSD which said it was not approved for 2007 and up diesel engines. Of course I filled up but I will have to stop by and ask them if it is really LSD.

I have seen 24mpg, but that was when fuel was $5+ and I was driving 64-72mph cross country.

 

[12ga diesel]

I've been running a cat back and I recently took it off. I noticed absolutely zero performance or mileage gain from getting rid of it. I did however drop about 100 degrees EGT's.

That's pretty interesting. I went straight from a stock exhaust to a downpipe back setup on my '06 LLY, so I really didn't have anything good to base my "seat of the pants" feeling except going from one extreme to another. I was thinking of going with a cat back set up when I decide to do the exhaust. But doing the turbo back set up was in the back of my mind as well. I will take into consideration your experience Nick when I do my exhaust.

 

[btfarm]

SUMMER BLEND! Oh Yeah!

I was starting to think there was something seriously wrong until the last couple of weeks. FINALLY getting a full shot of #2. Night and day difference in performance. The mileage is improving too but right now I'm having too much fun with the power ):h to get much better than 17.5.

 

[Ozzie]

Mine spends almost all of it's life pulling a trailer, so I can't check it anymore...either a heavy enclosed for work, or a large travel trailer.
I hardly ever get to see what it can do anymore...but it sure does pull sweet.
I'd like to think it's getting broke in real nice and when I'm not pulling it just wants to cut loose and play. ):h

All I have to go by is the onboard puter when I run empty...and that isn't for long enough to really know. I do have the club cab and a topper with shelving inside, so I know I wouldn't get what some of you do.