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Posted

Gas engine....  18.2mpg, 17.7mpg, 15.2mpg for 400 mi.

 

The 18.2 and 17.7 were set at the same trip, descending from the highest point in Ohio.  Couldn't believe when I saw that number on this truck.

 

The 15.2 was not set on a highway road trip, it was putting back and forth to work on rural roads.    Not surprisingly, the 80mph interstate driving trips don't give as good of mileage as my 50-55mph commute.

 

 

Posted

I would guess 17, 16, and 15, with 17 being on a country road that goes gently downhill averaging 50 mph, 16 being on a country road that is generally flat averaging 50 mph, and 15 being mostly on the interstate going 70 eastbound with a smidge of a tailwind.

Posted

My best has been 17.2 on a 2-hour trip to Lafayette running 60-65mph. Around town i usually get around 12. My truck has the 6.0 gas, not the diesel obviously!

Posted

Folks - I was seeing my mileage at 18 - 20 mpg - up until I had to replace my battery?

Not sure if it is a coincidence - not I seem to be averaging about 13.2 and best is about 16.

I have about 70K..

2014 GMC Sierra SLT.

Any thoughts?

Clean the fuel injectors?

Add an aditive to tank to clean the fuel system?

 

Thanks in advance.

JJ

Posted
L5P
 
28.7 - 25 miles
26.0 - 50 miles
22.8 - 400 miles 
 
4FECD751-C184-4B77-AFA9-F9C65671D365.thumb.jpeg.33a16d95ce40edf32603489c81f4de27.jpeg

25-28.4
50-27.8
400-20.8

These can’t be HD numbers?!
Posted
11 hours ago, Ryno12 said:

 

 


These can’t be HD numbers?!

 

Sorry.  No.  I didn't catch the HD part in the title.  Sorry

Posted
Sorry.  No.  I didn't catch the HD part in the title.  Sorry

Gotcha, no problem. I was thinking, damn, that’s impressive for an HD.
Posted

14, 14, and probably 14 ?

 

My "best" was at 17 when I bought truck...it's since changed to like 14.

 

Maybe it's issue with truck, or my driving style, or whatever - but she's a thirsty bitch. I love her anyway. :)

  • Like 1
Posted
8 hours ago, ewbldavis said:

14, 14, and probably 14 ?

 

My "best" was at 17 when I bought truck...it's since changed to like 14.

 

Maybe it's issue with truck, or my driving style, or whatever - but she's a thirsty bitch. I love her anyway. :)

sumbitch can handle anything though!

Posted (edited)

15 HD Deleted/tuned Duramax on 33x12.50x20. No interstate all around town 35-60mph. 

 

25-21.2
50-19.7
400-18.4

Edited by zmnypit
Posted
On 12/17/2019 at 9:58 AM, SILVER SLED said:

25-28.4

50-27.8

400-20.8

 

On 12/17/2019 at 9:44 PM, Ryno12 said:

These can’t be HD numbers?!

 

Sure they can....

When a Cdn truck is set to inch units instead of metric, it displays mpg for 31/62/404 instead of 25/50/400

 

My L5P currently is at

31  - 34.1

62 - 29.8

404 - 24.4

 

It has lots and lots of full tank averages over 20 mpg which means 600 miles between fillups.  On flat 2 lane with no wind I get the 'last 31' over 25 regularly.

Yes, it does lots of steady state driving with cruise on.

No, it doesn't tow much. 

 

DEF is a little over 1100 mpg.

 

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