Diesel Place banner

1 - 20 of 28 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
Hey guys just wondering what kind of mileage you are getting with your Dmax's. I have a 2003 Dmax and a 2003 8.1 with a Whipple Suppercharger. The 8.1 I am getting about 13 miles to the gallon with the blower and afew other mods. But the Dmax I am getting at best about 12 miles to the gallon. Shouldnt I be getting better mileage with the Dmax. The Dmax only has 4000 miles on it. When I pull my 33 toy hauler trailer I get about 9-10 miles to the gallon. Any ideas on getting better mileage on this beast .
 

·
Registered
Joined
·
958 Posts
I average about 20.5MPG, best I've seen was 24.3MPG. I drive with a light foot and the speed limits here keep me at an optimal cruising speed to see great mileage #'s.


Interstate cruising at 85MPH netted me 15-16MPG.
 

·
Registered
Joined
·
217 Posts
I get about 14 around town, short trips. On the highway I get about 16 at 80 mph, but about 18 at 65 mph. Pulling my 5200 lb boat I get about 14 doing 65 mph. My truck has 10,000 miles on it, and the mileage has been slowly improving over time.


John
 

·
Registered
Joined
·
1,558 Posts
Mileage will just vary from time to time. Temperatures, quality of fuel, sometimes additives and most importantly your foot. I haven't done any excessive towing with mine as of yet, but I have noticed that if I keep the RPM's around the 1900 range, my mileage is much improved. When I get into states with 70+mph limits, I lose 1-2 mpgs.
 

·
Registered
Joined
·
361 Posts
On my '02 ext cab 4x4 I got 18.5 on the highway or city every day. when towing 13-16 MPG. The funny thing is I can get the same fuel economy towing a empty 6 x 12 utility traler as the same trailer with 3k# of tractor on it.
A couple of times I broke 22 mpg going down hill with the wind at my back on a perfect day. On my '04 ( 1,300 miles ) I am getting ( by the computer ) 13 towing and 17.5 the rest of the time. I have a '03 Dodge 1500 4x4 reg cab with a hemi. 13 MPG day in and out. But it sure is fast and fun
 

·
Registered
Joined
·
267 Posts
blown2003hd said:
...But the Dmax I am getting at best about 12 miles to the gallon.

That's bunk. You should be able to get 16-20 on the highway (I'm at an honest 20mpg on the Hwy). City driving with the pedal into it, yeah I could see those figures...
 

·
Registered
Joined
·
5 Posts
Discussion Starter #9
thanks guys. I will watch more how I drive. If I see no change in the next month or so or next 2000 miles I think I might take it to the dealer.
 

·
Registered
Joined
·
74 Posts
<TABLE style="WIDTH: 725pt; BORDER-COLLAPSE: collapse" cellSpacing=0 cellPadding=0 width=963 border=0 x:str>
<COLGROUP>
<COL style="WIDTH: 48pt" span=2 width=64>
<COL style="WIDTH: 71pt; mso-width-source: userset; mso-width-alt: 3437" width=94>
<COL style="WIDTH: 71pt; mso-width-source: userset; mso-width-alt: 3437" width=94>
<COL style="WIDTH: 71pt; mso-width-source: userset; mso-width-alt: 3437" width=94>
<COL style="WIDTH: 82pt; mso-width-source: userset; mso-width-alt: 3986" width=109>
<COL style="WIDTH: 82pt; mso-width-source: userset; mso-width-alt: 3986" width=109>
<COL style="WIDTH: 60pt; mso-width-source: userset; mso-width-alt: 2925" width=80>
<COL style="WIDTH: 48pt" width=64>
<COL style="WIDTH: 49pt; mso-width-source: userset; mso-width-alt: 2377" width=65>
<COL style="WIDTH: 95pt; mso-width-source: userset; mso-width-alt: 4608" width=126>
<T>
<TR style="HEIGHT: 12.75pt" height=17>
<TD class=xl24 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; WIDTH: 48pt; BORDER-BOTTOM: #ece9d8; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" width=64 height=17>Mileage</TD>
<TD class=xl24 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; WIDTH: 48pt; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" width=64>Miles</TD>
<TD class=xl24 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; WIDTH: 71pt; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" width=94>Gallons</TD>
<TD class=xl24 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; WIDTH: 71pt; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" width=94>DIC Gals</TD>
<TD class=xl30 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; WIDTH: 71pt; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" width=94>Gals Error %</TD>
<TD class=xl26 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; WIDTH: 82pt; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" width=109>Cost</TD>
<TD class=xl24 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; WIDTH: 82pt; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" width=109>Avg MPH</TD>
<TD class=xl24 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; WIDTH: 60pt; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" width=80>MPG</TD>
<TD class=xl24 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; WIDTH: 48pt; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" width=64>DIC MPG</TD>
<TD class=xl24 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; WIDTH: 49pt; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" width=65>Error %</TD>
<TD class=xl24 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; WIDTH: 95pt; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" width=126>Notes</TD></TR>
<TR style="HEIGHT: 25.5pt" height=34>
<TD class=xl32 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; BORDER-BOTTOM: #ece9d8; HEIGHT: 25.5pt; BACKGROUND-COLOR: transparent" height=34 x:num>4494</TD>
<TD class=xl32 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" x:num>312.7</TD>
<TD class=xl32 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; BORDER-BOTTOM: #ece9d8; BACKGROUND-COLOR: transparent" x:num="19.015000000000001">19.015</TD>
<TD class=xl32 style="BORDER-RIGHT: #ece9d8; BORDER-TOP: #ece9d8; BORDER-LEFT: #ece9d8; BORDER-B
 

·
Registered
Joined
·
353 Posts
I have 11k on my 2003 dmax ext cab 4x4 and I am seeing close to the same results as ragtop. Granted I haven't got it down quite as nice as he does. Just a bunch of fuel reciepts with the miles wrote on them.



I would definately check into it with the stealer..





Mike
 

·
Registered
Joined
·
1,923 Posts
I saw those kinds of numbers when the truck was new (12mpg).... Especially when my foot was in it... after about 3 months with the juice my driving stabilized a little and the motor seemed to come together... I am around 19,xxx and the mileage has been going up slowly to about 15 around town, and 18 to 19 on the expressway... I never travel faster than 70 cause it goes down fast after that... Give it some time....





I think the six speed gives some of these guys better gas milage... By the way, my dad has the 6.0 gasser and has a hard time getting 14 on the expressway, and my uncle has the oil sucking 8.1 and he jump for joy when he see's 11... So whatever you did to your 8.1 is amazing...
 

·
Registered
Joined
·
5 Posts
Discussion Starter #15
all I really did before the Whipple was adding afew exhuast mods, headers and stuff and a programmer. So with all that with the blower and mods I get around 12-13 if I cruise at around 60 with cruise control on . Ilove the power on the 8.1. Oh someone asked me about what muffler . I used the 2 chamber flowmaster. Boy what a sound
 

·
Registered
Joined
·
64 Posts
Under load I get 16-18 depending on fuel stations and how heavy my foot is,


Unloaded between 19.5 and 22. Best I have seen is 25.2, this was done on a drive between Kansas City and Springfield, MO. All flat and unloaded, Speed was consistantly at 60 mph.
 

·
Registered
Joined
·
78 Posts
I have almost 50K on my Dmax. I changed the tire size since the speed limit in Colorado is 75. I went to the 255/85R16 to drop the RPM's a little. I average 20-22mpg on the highway and have gotten as good as 25mpg. I live 47 miles from work when I am in the country and it is all interstate so, those numbers are off all my fuel usage. Towing 8000lbs at the speed limits, I get around 14mpg. Towing that same weight at 100mph,
I get about 11mpg. These numbers are all from running through the mountains and living at 5200ft.
 

·
Registered
Joined
·
224 Posts
4000 miles - last fill 18.5 - and growing..
- It just keeps going up.. Where will it end..
 

·
Registered
Joined
·
94 Posts
blown2003hd said:
thanks guys. I will watch more how I drive. If I see no change in the next month or so or next 2000 miles I think I might take it to the dealer.

As an owner of a whipple supercharged 454 suburban, the big surprise is getting 13 with the blown 8.1. My blown 454 gets 10.5 on the fwy at best (but more like 9 regularly) and my buddy's 8.1 stock never got better than 11-12 at best.


My new duramax (bought it yesterday) has averaged 14 with 50/50 fwy city driving.
 

·
Registered
Joined
·
224 Posts
The blown 8.1 should get better MPG than a stock gasser, you're adding more air to the fuel which makes it burn better. As for the Dmax - just wait.. it keep going and going and going
My last fill came down a bit - but I added the Quad 110HP tow tune and about 4lbs of lead to my right foot
 
1 - 20 of 28 Posts
Top