• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Fuel Mileage Run for my 2006 Duramax

RI Chevy Silveradoman

RI Chevy Silveradoman

At your service
Staff member
Lead Moderator
Messages
15,521
Reaction score
11,895
Location
Rhode Island
I just recently attended the Nascar race in Loudon, NH last weekend. I hand calculated my fuel mileage which totaled about 85% highway, 15% city to a total of 425 miles with 18.530 gallons equaling 22.9 mpg. Not bad in my book.
 
Thats about what dad sees in his 07 LBZ. He is in love :) I think he is really glad that lady totaled his old truck (02 GMC 6.0 CCSB) last November.
 
RI Chevy Silveradoman said:
I just recently attended the Nascar race in Loudon, NH last weekend. I hand calculated my fuel mileage which totaled about 85% highway, 15% city to a total of 425 miles with 18.530 gallons equaling 22.9 mpg. Not bad in my book.
Click to expand...

About what I got years ago. On a combination of 2 and 4 lane roads, speeds from 45 MPH to 60 MPH the best I ever got was 22.8 MPG, hand calculated. I was headed to deer camp with probably 700 pounds of gear in the truck. I have tried a few times to beat that, but just can't do it. I either get in a headwind or traffic requires me to drive more aggressive and I use more fuel.
 
Not bat at 'tall. If you drive like a sane person, they get great mileage considering they're 7,000#

The absolute best I ever saw was 23.8 something on a 100% highway trip to ATL going no faster than 70 at an insanely early hour with no traffic.
 
That's excellent mileage Jeff:thumbsup:

20.00 is the best I ever got. Usually at 17.5-18.5. I don't complain and considering I run those aggressive tires it's pretty good.
 
With stock (or close to stock) size tires, just a tick below 2,000 @ 70.
They all have 3.73's.
 
Allison 6 speed ratios,

1st 3.10
2nd 1.81
3rd 1.41
4th 1.00
5th 0.71
6th 0.61
R 4.49

No wonder... Double overdrive.. A 6th gear of .61? That's nuts. No wonder these trucks pull so well and get the mileage.

I'd be curious of your MPG (not that you'd want to put yourself through it) if you were to run around in 4th.. Basically that is what my '93 K3500 with 4.10 axles and 'only' a .75 OD 4th gear is doing (revs wise) and getting 16.5 MPG...

Suffice to say, light truck diesel has come a long way.
 
And here I've been wishing I had a 7th gear for when I'm haulin asssss across Nebraska and NE Colorado at 85.
The best possible mileage you can get with these is after a 6th gear upshift at about 55, drop it back down to around 1325 RPM and poke the cruise button. Serious MPGs for 7000+ Lbs of truck!
 
Those are good numbers.

My truck has never seen anywhere near those numbers. My last trip to work I went 354 miles and used 21.6 gals 16.3 mpg. 300 miles were interstate cruise set at 70 mph 54 city. This was on my mileage tune. Best I've ever seen a little over 18mpg.
 
saratoga said:
With stock (or close to stock) size tires, just a tick below 2,000 @ 70.
They all have 3.73's.
Click to expand...

by "tick below" do you mean 1800 rpm? That's what it should be at 70 mph IIRC if your speedo is calibrated correctly. My tuner thru my speed off by 4 mph - even with the correct tire size selected on the tuner. Finally had to just play around with it until it was dead on. I'm running 265's but had to tell the tuner to select something weird like 242's to get it right.
 
I think the stock tire size height for 245's is 30.5 inches. 265's should be something along the lines of 31.7 or so inches. My tuner goes by inches or tire height from the ground to the top of the tire. I guess it would be diameter. :rof:
 
UPDATE. I just did a 93% highway run and got 24.06 mpg. I run a Hypertech tune and it is set on stage 3. I also use a fuel supplement in every tank.
353.03 miles and used 14.631 gallons equals 24.06 MPG. I am pretty satisfied. I pretty much ran at about 63 mph on cruise control.
A few times I did get up to 70 for a while until I realized that I was going fast, and then back on the cruise.
 
Last edited:
btfarm said:
And here I've been wishing I had a 7th gear for when I'm haulin asssss across Nebraska and NE Colorado at 85.
The best possible mileage you can get with these is after a 6th gear upshift at about 55, drop it back down to around 1325 RPM and poke the cruise button. Serious MPGs for 7000+ Lbs of truck!
Click to expand...

Ive seen 23.4 with this method ~56mph with my larger tires doing stop and go field checking while watching my boost and using the load meter on my Edge. At 62mph im only turning ~1400 rpm (where my truck has that damn vibration) and is where i normally cruise and get mid 19's highway and mid 17's doing stop and go farm checking and some idle time.
 
MPG's While Towing

Just an update.

While towing my travel trailer to NH, I averaged 11.67 mpg. 203.2 miles devided by 17.408 gallons of #2 diesel = 11.67 mpg.
Not great, but not that bad either. I was averaging about 63 mph while using the tow/haul engaged in the Allison. About 1900 rpm's while on the highway.
 
That's about what I got in my LBZ on my Trip down to FL a few Years ago, Low / Mid 20's.

I'm Happy with it :)
 
I just can't fathom how you guys can drive 63-70 mph?

I'm at 77-80 all the time empty...towing I'm around 73-77
 
You must log in or register to reply here.
Back
Top