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6.2l Sierra/Silverodo/Denali - L/100KM - Fuel Economy

Nvd

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Nvd Enthusiast

Nvd

Posted
Posted

I have done some research and have found some info but would like a little more. Sorry if this is "another thread" on same topic but..

 

I was looking into getting a GMC sierra slt 5.3l v8 w/afm system. But according to my research they have had a lot of issues and I didnt want to run into that after spending 30k. I still want a gm tho, couldn't see my self in a ford or dodge...

 

Im looking at the 6.2l v8 that doesnt have the afm system. Now my questions are:

 

1)i have seen ppl avg 13-20mpg but wondering how many miles and or km you guys are getting per tank. I have done the math to convert the mpg to km/tank approx but i think i might be off a little.

 

2)the 6.2l in the sierra and silverodo i think has a dial that you can change it from 4x4 to 2hi or 2lo or auto, and the denali just has the AWD. Would by having it in the 2wd save much on fuel vs the AWD denali?

 

Anyone that was in my shoes once and where debating between a 6.2l or the 5.3. Which truck did you go with and are you glad with that one or do you wish you had the other?

 

Im looking to get as much info as possibly before i make my choice.

 

Thanks in advance!!

Nick

Svenleven Enthusiast

Svenleven

Posted
Posted

This is a reply to a similar thread that I had:

I had an 08 Sierra with the 5.3l and 4 speed and on the same 5 hour highway road trip I make several times a year, I was always averaging 14.0l/100km (works to 16.8 mpg US). With my 6.2l with the 6 speed, my last 2 trips where 12.8l/100km (18.3mpg US). This is driving ~120km/hr and passing from time to time. The conclusion I draw from this is the 6 speed making a significant difference. I imagine with the 5.3l, you would get at least a little better. In 4 years and 113000km, I never lost a drop of oil in it either, for all the stories you hear on here about oil consumption. I don't think the AFM does anything noticeable the fuel mileage in my opinion.

 

I would get the 5.3l 6 speed over the 4.8l 4 speed in a heart beat.

 

That said, I never really track city mileage cause it's so hard to be consistent to compare, but the 6.2l seems a little thirstier then the 5.3l there. Which is too be expected. Not sure how the 4.8l would compare there.

 

 

1) That would have had my 460km trips leaving about 1/4 tank, so I'm gonna saying in the neighborhood of 600km/tank as a conservative estimate

2) From my above post, I actually was getting better highway mileage with the 6.2l AWD then my 5.3l selectable (running in 2wd). But the transmission is the big difference here. I have no experience with the 5.3l setup with the 6 speed.

 

I am extremely happy with my 6.2l, I don't think I could go back to a 5.3l. Especially with it BB tuned.

mymaggiebell Enthusiast

mymaggiebell

Posted
Posted

+1

i just did a fill after having justin tune it, and it is awesome! 5.3 is very good and would never knock it, but will be sad to move on after this!! i had tune installed recently on for part tank and my readout on computer was 648km after filling up and i know i would never see that before! multiple friends own newer avalanches, tahoes, etc, and they are not getting a significant amount of mpg savings over me.

mymaggiebell Enthusiast

mymaggiebell

Posted
Posted

oh yeah, need to add that justin and the blackbear tune is awesome from my end!!! everything that was/has been said is the truth!! from honking on it to just driving it, the truck is better!! 6.2 went from cool to awesome!! sorry thought i would add this too!!

cracked_up Enthusiast

cracked_up

Posted
Posted

My daily commute is 4 miles round trip, I get ~13mpg on 33" tires with a BB Tune. Average 300mi+ per tank.

Very happy with the 6.2 I get the same mileage as my 2002 5.3 did with a lot more power.

RyanbabZ71 Senior Enthusiast

RyanbabZ71

Posted
Posted

With my larger tires and E85 I have been getting about 9.5 mpg :).

 

 

Ryan

Nvd Enthusiast

Nvd

Posted
  • Author
Posted

+1

i just did a fill after having justin tune it, and it is awesome! 5.3 is very good and would never knock it, but will be sad to move on after this!! i had tune installed recently on for part tank and my readout on computer was 648km after filling up and i know i would never see that before! multiple friends own newer avalanches, tahoes, etc, and they are not getting a significant amount of mpg savings over me.

 

 

Nice! And you have the 6.2l correct?

 

Thx

Nvd Enthusiast

Nvd

Posted
  • Author
Posted

Alright good to hear! So if I were to get a 6.2l Denali, I can expect over the 600km/tank (if I drive it good and don't step on it) i do maybe 30% city 70% hiwy !

2010LTZ4x4 Enthusiast

2010LTZ4x4

Posted
Posted

Alright good to hear! So if I were to get a 6.2l Denali, I can expect over the 600km/tank (if I drive it good and don't step on it) i do maybe 30% city 70% hiwy !

 

Good luck on the 600km/tank. 500 is more realistic with the AWD 6.2 Denali.(drive it good and don't step on it)

I'm lucky to get 400-425 with my 6.2, but I drive 90% in town and my foot is always into it.

On the hwy the lowest I can get the fuel estimater down to is 13.5L/100km and in town 19L/100km.

joshw1303 Enthusiast

joshw1303

Posted
Posted

Oh yea if mostly hwy, you should do fine. My 5.3L says i could do over 726 km on tank. See the computer changes with how you drive. If you keep doing hwy mileage. It will tune it and you will see better mpg. I just wish my 5.3 had some more torque.

joshw1303 Enthusiast

joshw1303

Posted
Posted

Alright good to hear! So if I were to get a 6.2l Denali, I can expect over the 600km/tank (if I drive it good and don't step on it) i do maybe 30% city 70% hiwy !

 

Good luck on the 600km/tank. 500 is more realistic with the AWD 6.2 Denali.(drive it good and don't step on it)

I'm lucky to get 400-425 with my 6.2, but I drive 90% in town and my foot is always into it.

On the hwy the lowest I can get the fuel estimater down to is 13.5L/100km and in town 19L/100km.

 

 

Wow that is pretty good. I am seeing mid 300kms for in town driving. over a week and half almost empty. On top end ive seen almost 730 km hwy. I usually get 18l per 100 in city and goes down to 12.5l per 100 . I wish i got the 6.2 lol.

Nvd Enthusiast

Nvd

Posted
  • Author
Posted

Im confused...

 

I see people saying they get 15mpg (low) 21mpg (hi) on the 5.3 and 19mpg (hi) and 15mpg (low) on the 6.2..

according to my calcs at that would equal to the following:

 

5.3l

15MPG = 622 km/tank minus 15% = 529km/tank

21MPG = 871 km/tank minus 15% = 741km/tank

 

6.2

15MPG= 622 km/tank minus 15% = 529km/tank

19MPG= 787 km/tank minus 15% = 669km/tank

 

I minused 15% to be on the safe side and account for road and driving conditions..

 

Im pretty sure what i did is correct,

KM/Tank=[(mpg*1.6)/3.78]*Tank capacity in liters

im using a 98L tank as well, 1mile=1.6km and 1g=3.78L.

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