miles per gallon with the v8

06envoydenali

Original poster
Member
Dec 5, 2011
52
After seeing a thread for the v6 engines I was curious to know what people with the 5.3 are getting. My dash says im getting 10.8. Im doing mostly city and a little highway about 80/20. I drive semi fast, always like to here humm of the cai.:thumbsup: Is this the normal milage you guys are getting? also im 4x4.
 

northcreek

Member
Jan 15, 2012
3,295
WNY
06envoydenali said:
After seeing a thread for the v6 engines I was curious to know what people with the 5.3 are getting. My dash says im getting 10.8. Im doing mostly city and a little highway about 80/20. I drive semi fast, always like to here humm of the cai.:thumbsup: Is this the normal milage you guys are getting? also im 4x4.

These trucks have either the I6 or V8 not V6.My Denali is getting 17+ right now and 18+ in the summer(town and secondary roads). Many people here say that the winter gas gets poorer mileage. I thought it would be better in winter with the A/C off but, that's not the case.
Your 10.8 is not typical unless you're driving around with the E-brake on :eek: ...Mike.
 

navigator

Member
Dec 3, 2011
504
06envoydenali said:
After seeing a thread for the v6 engines I was curious to know what people with the 5.3 are getting. My dash says im getting 10.8. Im doing mostly city and a little highway about 80/20. I drive semi fast, always like to here humm of the cai.:thumbsup: Is this the normal milage you guys are getting? also im 4x4.

if you take off rather quick and stop pretty quick you'll kill your gas mileage.
We recently got a Suburban with the DIC and I can see that coasting to a stop and taking off easy really helps the mileage.
I got around 10 mpg my first tank but by making a few changes I am up a little over 14 mpg. These are mostly short trips, car pool lines at school and an occasional 20-30 mile trip.
 

DFWWIZ

Member
Dec 5, 2011
516
I'm averaging 13.1 with a very built 6.0, 3200 stall in 90% city driving. Before this, with just a few mods, it was 16 city and 20 HWY. I can still get pretty close to 20 HWY if I stay at or below 70 MPH. I drive fairly brisk in the city, its hard not to when you have 500 HP on tap and built trans with 3200 stall. :yes:
 

tokahao

Member
Dec 9, 2011
79
I have the 5.3L V8 w/4x4 and averaging about 16.4 in the city. Don't do much hwy driving here on Oahu so can't really say. Also I use 91 octane, always, coz my pockets are deep like that :rotfl: (but not really)
 

Instrumental

Member
Jan 29, 2012
268
I use an fuel logging app to track, don't really trust the display. My stats are:

Best ever MPG 18.65 (just about all highway)

Worst ever 11.65 (lotta towing, short trips)

Average is 15.1 over 9 months.


On a related note, is there a way to set the trucks mpg readout to be real time rather then having to reset it every tank? I drove a rental that was real time and it was great to get instant feedback on my driving choices.
 

northcreek

Member
Jan 15, 2012
3,295
WNY
Instrumental said:
I use an fuel logging app to track, don't really trust the display.

I did the math and my DIC display was almost to the tenth in accuracy.
 

C-ya

Member
Aug 24, 2012
1,098
DOD/AFM in mine. Best MPG: 16.75; worst: 10.38; average (over 26 fill ups): 13.1

My driving is 3-5 mile trips twice a day, 5 days a week, with the occasional 35 mile trip to the airport and home a day or 3 later.

My DIC is pretty doggone close to hand figuring also and as well.
 

Jkust

Member
Dec 4, 2011
945
Well i've had three of our platform all with the 5.3 and two of them with DOD so have years of experience in all conditions and towing. I can give you stats all day but here's what i'll say. Winter blend gas kills the MPG's. Im talking 5mpg's less per gallon per tank. Also, the DIC is spot on with the manual calc. I instantly can tell when the winter blend switches to spring or summer or whatever they call it. It's like I unhooked a trailer. Keeping the rpm's around 2k and not much higher seems to maximize the highway mpg's. All of my 360's have had the extra mpg penalty of 4awd as well. I'd have hoped trucks with v8's would be getting 30mpg by now.
 

dcarver

Member
Mar 17, 2013
5
We've had the rainier for a few months but have filled up about 6-7 times in city mileage and its been 16-17. 1000 mile trip home averaged 20mpg even driving 70-80mph. I10 is a fantastic hwy so that's probably where the good mpgs and driving 80mph comes from
 

TollKeeper

Supporting Donor
Member
Dec 3, 2011
8,027
Brighton, CO
My MPG is going to be way low, as I only drive my Voy about 200 miles a month. But I average 13.2. When I do go out and stretch her legs, I usually get anywhere from 18.0 up to 21.7. It all depends on the gas (E10 vs E0), and the terrain.
 

Jkust

Member
Dec 4, 2011
945
TollKeeper said:
My MPG is going to be way low, as I only drive my Voy about 200 miles a month. But I average 13.2. When I do go out and stretch her legs, I usually get anywhere from 18.0 up to 21.7. It all depends on the gas (E10 vs E0), and the terrain.

I'd love some E0 gas... but the spots it's available it is high octane and costs more than the milege offset.
 

DenaliHD66

Member
Dec 4, 2011
597
Instrumental said:
On a related note, is there a way to set the trucks mpg readout to be real time rather then having to reset it every tank?

Get a Scangauge. It's on my list to buy...eventually.
 

Jkust

Member
Dec 4, 2011
945
As a novelty, I wish we had the instant econ that every single car i've ever owned back to my 1984 Chrysler Laser's have had. Every other GM I've driven has this feature no matter how cheap a car.
 

C-ya

Member
Aug 24, 2012
1,098
Jkust said:
As a novelty, I wish we had the instant econ that every single car i've ever owned back to my 1984 Chrysler Laser's have had. Every other GM I've driven has this feature no matter how cheap a car.

To juxtapose against your results, I've never owned a vehicle with instant economy. Ehh, maybe my '93 300ZX had it - I can't remember.
 

Jkust

Member
Dec 4, 2011
945
C-ya said:
To juxtapose against your results, I've never owned a vehicle with instant economy. Ehh, maybe my '93 300ZX had it - I can't remember.

Even my 1989 Chevy Beretta had it way back when. Both my Bonnevilles, my Olds minivan, Chevy Corsica, two 84 Chrysler lasers, Eagle vision TSI (best car I ever owned) and I think my 86 Toyota Celic GTS had it as well. Also every GM loaner or rental has had it...even the clownish HHR had it and even had tranny temp.
 

MoJoRisin'

Member
Jan 11, 2013
22
Mine is a 2004 non DOD, and I'm in the 14-15 range mostly city - short enough trips (2 miles or less) where it does not heat up real well either. Highway is around 18.

Better than my 2000 K3500 7.4L / 454 which gets 10 on a good day and 8 fully loaded with campertopper and 20 ft boat. I think it runs better under full load actually.
 

Jkust

Member
Dec 4, 2011
945
MoJoRisin';126805 said:
Mine is a 2004 non DOD, and I'm in the 14-15 range mostly city - short enough trips (2 miles or less) where it does not heat up real well either. Highway is around 18.

My Wife's Rainier is an 07 with dod and her trips are maybe a mile at most. I get in on the weekends when we drive her car somewhere and the dic is at 11.5mpg's a lot of times. Even towing the boat it gets 12ish.
 

06envoydenali

Original poster
Member
Dec 5, 2011
52
in response to pretty much everyone (b/c your all getting much better milage) what could be some issues that cause such poor mpg (10.8)... :confused:
 

tokahao

Member
Dec 9, 2011
79
06envoydenali said:
in response to pretty much everyone (b/c your all getting much better milage) what could be some issues that cause such poor mpg (10.8)... :confused:

Tire pressure, bad alignment or bad thermostat maybe?
 

06envoydenali

Original poster
Member
Dec 5, 2011
52
tokahao said:
Tire pressure, bad alignment or bad thermostat maybe?

tire pressure i know is good. Alignment i would be able to feel a pull when I let go of the wheel right? and how would i go about checking the thermo?
 

northcreek

Member
Jan 15, 2012
3,295
WNY
06envoydenali said:
in response to pretty much everyone (b/c your all getting much better milage) what could be some issues that cause such poor mpg (10.8)... :confused:

Are you burning oil? Some 5.3 engines have oil burning issues, usually due to a valve cover baffle(but there can be other reasons).Burning oil could have a drain on the engine's efficiency by diluting fuel...Mike.

ps a plugged Cat could also be a cause.
 

06envoydenali

Original poster
Member
Dec 5, 2011
52
northcreek said:
Are you burning oil? Some 5.3 engines have oil burning issues, usually due to a valve cover baffle(but there can be other reasons).Burning oil could have a drain on the engine's efficiency by diluting fuel...Mike.

I check my oil level every month(ish) it doesn't seem to be a problem... however, i did get my engine completely replaced (2010) due to the prior owner NEVER changing the oil (put about 65,000 on it)... I would assume there could be a whole list of problems that could of occurred during that process.. is there anything i should ask to check next time i bring it to the shop?
 

northcreek

Member
Jan 15, 2012
3,295
WNY
06envoydenali said:
I check my oil level every month(ish) it doesn't seem to be a problem... however, i did get my engine completely replaced (2010) due to the prior owner NEVER changing the oil (put about 65,000 on it)... I would assume there could be a whole list of problems that could of occurred during that process.. is there anything i should ask to check next time i bring it to the shop?

If that is the original Cat from the smoked engine,I would have it checked for flow.
 

tokahao

Member
Dec 9, 2011
79
^^ What he said! :undecided:

06envoydenali said:
tire pressure i know is good. Alignment i would be able to feel a pull when I let go of the wheel right? and how would i go about checking the thermo?

From what I've heard the temp gauge should be very close to half or just above the half-line. Anything short would mean your engine is running cooler than normal, causing your vehicle to want to run richer to raise the temp. Again, I've only heard this stuff--I want to be wrong.
 

Denali n DOO

Member
May 22, 2012
5,596
Well my mpg on the dic, after few days hiway driving sitting at 19.6 mpg. I reset dic every fill up.

Hook up a scan tool and verify engine operating temperature, gauge isn't accurate, 195 is good and I think less than 185 is no good. Also look at long term fuel trims. This info may help diagnose the issue.
 

C-ya

Member
Aug 24, 2012
1,098
06envoydenali said:
in response to pretty much everyone (b/c your all getting much better milage) what could be some issues that cause such poor mpg (10.8)... :confused:

The weight of your right foot? I find I get better mileage by shifting below 2K rpm, easing out of stops, and coasting and braking to a stop, not driving right up to the stop then jamming on the brakes. Here lately, I'm averaging 12 - 12.5 mpg with the winter gas and my short trips.
 

Denali n DOO

Member
May 22, 2012
5,596
C-ya said:
The weight of your right foot? I find I get better mileage by shifting below 2K rpm, easing out of stops, and coasting and braking to a stop, not driving right up to the stop then jamming on the brakes. Here lately, I'm averaging 12 - 12.5 mpg with the winter gas and my short trips.

My mpg would be about same as yours if I was driving around town and/or pulling trailer, I'm amazed how much more fuel efficiant these motors are when driving on the hi-way. Best I've ever seen on the dic was 22.4 mpg or 10.5 L/100km, on a one way trip west to east on the hiway, probably had a tail wind.
 

Jkust

Member
Dec 4, 2011
945
Denali n DOO said:
My mpg would be about same as yours if I was driving around town and/or pulling trailer, I'm amazed how much more fuel efficiant these motors are when driving on the hi-way. Best I've ever seen on the dic was 22.4 mpg or 10.5 L/100km, on a one way trip west to east on the hiway, probably had a tail wind.

Totally agree on the wind situation. When towing a trailer the wind directiona and speed makes a huge difference in the MPG's. Sometimes towing the 4000lb boat I've gotten astoundingly good mpg's upwards to 18+ with a heavy tail wind. Only happened a couple times but it has happened. I could swear the DOD must be kicking in but of course that isn't possible when towing.
 

C-ya

Member
Aug 24, 2012
1,098
Just filled up today and had 14.7 mpg (DIC 14.2) on this tank (over 50% highway, tho). Last tank was 13.4 mpg (DIC 13.1). I think it is a combination of coming out of winter gas and the fuel treatment I have started using. I'm using Star Brite's Star Tron (Star Tron Enzyme Fuel Treatment - HOME) in the TB and Gumout's ethanol fuel treatment (GUMOUT® - Ethanol Fuel Treatment) in the wife's Impala. I am noticing both vehicles getting better mileage.
 

GS_Geoff

Member
Jul 7, 2012
21
13.6mpg in the winter with 95% city driving and winter gas. Summer is more like 14.2mpg city. Highway I get 20-21.

That's in an 08 9-7x with 52k miles.

EDIT: Forgot it doesn't display vehicle under your name...
 

TollKeeper

Supporting Donor
Member
Dec 3, 2011
8,027
Brighton, CO
Been driving my XUV V8 hard this last week. 800 miles since Saturday.. Averaging 17.6, and I have not been gentle on the skinny pedal.. I think my upstream O2 sensor maybe getting lazy..
 

DDonnie

Member
Mar 26, 2012
2,631
I'm getting a steady 13.1 100% city
 

northcreek

Member
Jan 15, 2012
3,295
WNY
Getting 17.6 mpg right now,mostly rural & village driving,rolling country with a few steep hills.A/C on 25%..Mike.
 

Jkust

Member
Dec 4, 2011
945
northcreek said:
Getting 17.6 mpg right now,mostly rural & village driving,rolling country with a few steep hills.A/C on 25%..Mike.

Now that it is warmer and winter fuel blend has been gone a while...I now get the standard 17.5 - 17.9 per tank commuting mpg's. That means 90% highway but hit and miss stop and go. On the highway however the truck will get up to 24mpg's if it's all highway...then it slowly starts to normalize the more stop and go there is. I can never figure out why sometime's it will be 24 and others it will be 22 all else equal.
 

northcreek

Member
Jan 15, 2012
3,295
WNY
Jkust said:
I can never figure out why sometime's it will be 24 and others it will be 22 all else equal.

My guess would be wind direction.:undecided:
 

GMDUDE2003

Member
Apr 10, 2012
78
I bought her in November last year and was getting 17.3 average, but as of right now 16.1 mpg but shes ready for an oil change and I'm not sure when they stop using "winter blend" here in Northern Ohio.....
 
Dec 4, 2011
515
GMDUDE2003 said:
I bought her in November last year and was getting 17.3 average, but as of right now 16.1 mpg but shes ready for an oil change and I'm not sure when they stop using "winter blend" here in Northern Ohio.....

I think Ohio (sorry I mean Northern Ohio) is about 2 weeks before us here in Saskatchewan Canada. I think the date here is mid to late August then they get ready for winter blend about mid Sept. :rotfl:
 

GMDUDE2003

Member
Apr 10, 2012
78
RedEnvoyDenali said:
I think Ohio (sorry I mean Northern Ohio) is about 2 weeks before us here in Saskatchewan Canada. I think the date here is mid to late August then they get ready for winter blend about mid Sept. :rotfl:

It would make sense to me lmao :biggrin:
 

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