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Posted (edited)

Hey Everyone, new to the forum. I have 2021 GMC Sierra 1500 AT4 3.0 diesel. What are you guys getting on your MPG? If your getting 30+ mpg what speed are you driving? I'm getting 23 to 24 average hand Calculated and that driving 70% hwy. Thats driving between 70 to 80 mph on the hwy. I see people on YouTube getting 30+ mpg. The only way I can see me doing that is driving 55 mph on the hwy. I would like to hear what you guys are getting.  

Edited by Cuongdyna
Posted
17 minutes ago, Cuongdyna said:

Hey Everyone, new to the forum. I have 2021 GMC Sierra 1500 AT4. What are you guys getting on your MPG? If your getting 30+ mpg what speed are you driving? I'm getting 23 to 24 average hand Calculated and that driving 70% hwy. Thats drive between 70 to 80 mph. I see people on YouTube getting 30+ mpg. The only way I can see me doing that us driving 55 mph on the hwy. I would like to hear what you guys are getting.  

If you have a 2wd with the 3.0L Duramax and low rolling resistance street tires, maybe 30 MPG is in the realm of possibility.  I've got 27.4 MPG with my LTZ Z71 3.0L Duramax for comparison.  Getting anymore than that would be a challenge.

 

No way 30 MPG is happening in an AT4 which has a 2in lift (increasing drag resistance) and AT tires (increased rolling resistance).

 

Go for a cruise at 55 or 65 MPH and you'll get about the best MPG you can squeeze out.

 

There are so many factors that play into MPG: Altitude, air temperature, relative humidity, headwinds, tailwinds, if its raining, what accessories you may or may not have installed, etc. 

Posted

Mine is brand new.  DIC shows 24.5 MPG average for the first 180 miles, 50/50 highway/city.  It's cold here so I used the remote start twice.

 

Keep in mind that it take time for the engine to break in, it's cold and winter fuel (diesel or gas) carries less energy.

Posted

I’m roughly seeing these figures consistently. Flat drive, elevation sea level. 

60mph ~ 33mpg

65pmh ~ 30mpg

70mph ~ 26mpg

75mph ~ 23mpg

80mph ~ 20mpg

 

 

  • Thanks 1
Posted
3 minutes ago, Duramax3oh said:

I’m roughly seeing these figures consistently. Flat drive, elevation sea level. 

60mph ~ 33mpg

65pmh ~ 30mpg

70mph ~ 26mpg

75mph ~ 23mpg

80mph ~ 20mpg

 

 

Nice! Is your truck 2X4 or 4X4?

Posted (edited)
3 hours ago, btj_z71 said:

If you have a 2wd with the 3.0L Duramax and low rolling resistance street tires, maybe 30 MPG is in the realm of possibility.  I've got 27.4 MPG with my LTZ Z71 3.0L Duramax for comparison.  Getting anymore than that would be a challenge.

 

No way 30 MPG is happening in an AT4 which has a 2in lift (increasing drag resistance) and AT tires (increased rolling resistance).

 

Go for a cruise at 55 or 65 MPH and you'll get about the best MPG you can squeeze out.

 

There are so many factors that play into MPG: Altitude, air temperature, relative humidity, headwinds, tailwinds, if its raining, what accessories you may or may not have installed, etc. 

I averaged 36 and some change for 25 miles going 55 thru Tennessee. BFG All terrains and the AT4 lift on my 5.3 X31 SLT. 

E717A5CE-CE90-487B-9044-6BCA566BDF0B.jpeg

Edited by Jason Rebellion
Posted
9 hours ago, Jason Rebellion said:

I averaged 36 and some change for 25 miles going 55 thru Tennessee. BFG All terrains and the AT4 lift on my 5.3 X31 SLT. 

Which hill were you going down?

Posted
8 minutes ago, f8l vnm said:

I sometimes average 99 MPG when I go downhill :)

Me too?

 

5 minutes ago, Salsa De Piña said:

Which hill were you going down?

You know, that hill?

Posted
12 hours ago, btj_z71 said:

There are so many factors that play into MPG: Altitude, air temperature, relative humidity, headwinds, tailwinds, if its raining, what accessories you may or may not have installed, etc. 

Well, there ya go

Posted

I don't like to use the instant mpg reading other than to get a vague idea of the general range we may be talking about.

 

I take a lot of long highway trips and prefer to set cruise control at different speeds and then see how the 25-mile avg and 50-mile avg readouts look. It's hard to get any more accurate than that IMO.  Particularly when you do that on I-10 in Texas and Louisiana... there is NO DOWNHILL ?

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