2010 Denali/Mileage Question

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Doubeleive

Wes
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Why does my 2010 Yukon Denali 6.2, only get 13 miles per gallon?
because your pushing the big pedal, try granny style @55 and minimal braking, ease on the pedal like you are going to take all day to get up to speed. coast whenever possible.
other than that these are not "economical" vehicles if you are concerned about mpg go by a prius
 

Marky Dissod

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Why does my 2010 Yukon Denali 6.2L, only get 13MpG?
Even if it is not an XL, it still weighs at last 5000lb. (XLs weigh closer to 6000lb.)
If using 87 instead of 91, MpG will decrease. How much does ethanol cost compared to 87?
Unless towing / hauling heavy, 50% 87 octane with 50% ethanol works grreat!
(If towing / hauling heavy, use 67% 91 octane with 33% ethanol.)

Wait a sec: do you use ethanol? Ethanol ALWAYS gets worse MpG compared to petrol,
even though it may very well get better miles per DOLLAR, depending on prices of 87 vs ethanol.
Ethanol also burns cleaner and improves emissions, so even if miles per dollar is same as petrol,
in the very long run, your engine comes out ahead.

Are you leadfooted? Leave earlier, and lighten up on the go-pedal as much as you can stand it.
If EVERYONE is passing you, you're getting better at it. (Bonus points for slowing others down.)
Coast as much as reasonably possible, pretend there's something wrong with the brakes,
and see if you can get better at approaching red lights just as they're about to turn green.
Don't idle in Neutral / Park unless the heater / AC is needed.

Hypermiling: the art of driving to save enough petrol to piss off everyone else so profoundly,
that they waste THEIR petrol instead of your time. Did I mention, leave earlier?

How old are your O2 sensors / spark plugs / wires?

Is your air filter clean?

EDIT: forgot to mention:
Are you using 10W40, or 5W20?
How old is your axle gear oil / differential fluid / ATF?

How bad is your alignment?
Are any of your brakes dragging?
 
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rdezs

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Something's wrong, you should be getting a lot better mileage. Our 2014 with the same L94 averaged 17.2 MPG until I deleted the AFM/DOD at 142,000 miles. (After the delete, running the Diablo sport economy tune, we're at 168,000 mi with an overall average of 18.8)

How's your air filter? Spark plugs? Any codes stored? If the basic stuff checks out, I'd throw a new AC Delco camshaft position sensor in, and crankshaft position sensor. They are known to go bad without throwing a code. The L94 does not get good mileage from the AFM/DOD system.... It gets it from variable valve timing, which depends on the camshaft position sensor to work properly. (Which works in tandem with the crankshaft position sensor) With its ability to retard camshaft timing at lower RPMs, you make a lot more torque which equals more efficiency right where you need it, at cruising speed. That's my guess anyway
 

Doubeleive

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Something's wrong, you should be getting a lot better mileage. Our 2014 with the same L94 averaged 17.2 MPG until I deleted the AFM/DOD at 142,000 miles. (After the delete, running the Diablo sport economy tune, we're at 168,000 mi with an overall average of 18.8)

How's your air filter? Spark plugs? Any codes stored? If the basic stuff checks out, I'd throw a new AC Delco camshaft position sensor in, and crankshaft position sensor. They are known to go bad without throwing a code. The L94 does not get good mileage from the AFM/DOD system.... It gets it from variable valve timing, which depends on the camshaft position sensor to work properly. (Which works in tandem with the crankshaft position sensor) With its ability to retard camshaft timing at lower RPMs, you make a lot more torque which equals more efficiency right where you need it, at cruising speed. That's my guess anyway
Lol, what about me...
I get 9.6, what's your synopsis I wanna hear this one
 

rdezs

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I'll add the vehicle runs perfectly the tires are inflated properly and transmission is in good working condition, spark plugs/wires have about 10k on them or less and I use 93 octane
.... So something's definitely off. We use 92 octane on long road trips, like the 900 miles to Vegas and it nets us 20 MPG. I'm wondering if you're getting close to having the catalytic converters plugged. Maybe not enough yet to set the code. How old is the muffler? Did the plugs look good when you changed them? Wouldn't hurt to plug in and check the fuel tables and such...
 

Foggy

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My 14 on the window sticker says 13mpg city/ 18 mpg highway.
That's certainly a pipe dream of the OEMs.. as that's tested at ideal conditions
on a NEW vehicle. When I was totally stock I got 17.2 hwy. With DOD just
disabled I got 17.0 !!!!
So if your driving in urban/suburban traffic 13 is pretty normal ish
Do the maint as suggested above and make sure your tires and alignment
are "right"
 

wjburken

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My wife’s 2013 Denali XL averages between 14 & 15 mpg. She does a fairly even mix of highway and city.

This is right online with what we got on our 2007, 2008 Denali XL’s and our 2009 Suburban.
 

Doubeleive

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.... So something's definitely off. We use 92 octane on long road trips, like the 900 miles to Vegas and it nets us 20 MPG. I'm wondering if you're getting close to having the catalytic converters plugged. Maybe not enough yet to set the code. How old is the muffler? Did the plugs look good when you changed them? Wouldn't hurt to plug in and check the fuel tables and such...
Cats are new less than a year old each, it's none of the above, it's just how I drive. I can take a brand new one off the lot and get the same mpg
 

petethepug

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2010 YXL Denali with fire breathing 6.2L?

13 MPG is good. Did you end up transporting it or flying out to get it?

Your milage is great. 2011 may have an instant milage calculator and average trip calculator. If you want to know what highway mileage is just reset the milage calculator while you’re at highway speed.
IMG_2702.jpeg


 

Joseph Garcia

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My 2007 Yukon XL Denali averages 10-12 mpg in the city (occasionally dropping below 10), 14-16 mpg on the highway, and 18 mpg on the highway with my wife sitting next to me. :chair:

I run 93 octane exclusively.

Like @Doubeleive , I drive it like I stole it. Otherwise, it is no fun.
 
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rdezs

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That sounds about right, driving it normally. It's also a pretty good indicator on the condition of the engine in general
 

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