2014+ Gas Mileage (MPG) Topic

mdes0 · February 24, 2014

First highway trip with the Denali 6.2:

I have 34" tires and have not corrected the computer. Adjusting for the 7.4% error the actual numbers are 17.3 MPG at a 68 MPH average.

This was a round trip from the Seattle area to the top of Snoqualmie Pass (3000 ft elevation) and back again. The engine is still new (fewer than 300 total miles).

I'm pretty happy with that. It's rated at 20 for the highway, I've taken off the front airdam, lifted it 2" front, 1" rear, and put much bigger and heavier 34" tires on it.

On flatter ground it should easily be in the 18-19 range, mountain passes kill your mileage. So I think that's pretty good considering what this engine is capable of when you put your foot down.

What size tires did you go with? Any rubbing?

My gas milage has been in the crapper since the recall flash. I'm lucky to see 17 on the highway! Seems to get better mileage under 60.

fondupot · February 24, 2014

That average speed screen is nice. I wish my SLT model had that. Must only be on Denali.

Edited February 24, 2014 by fondupot

Jon A · February 24, 2014

The tires are 275/65R20 Duratracs, 34.1" OD. No rubbing yet.

Dnt · February 25, 2014

That average speed screen is nice. I wish my SLT model had that. Must only be on Denali.

I saw that too, I was also wondering if the DIC has an option for the average mph on the lowly SLT or is this Denali only?

Edited February 25, 2014 by Dnt

dfwvtxman · February 25, 2014

Bought an 2014 Silverado LTZ 2 wheel drive. Thru 3 tanks I'm getting anywhere from 10.8 thru 13 mpg. Mainly city driving yes, but a couple 75 mile city/highway combinded trips thrown in there. Got the highest MPG during the 1st tank., Then had the recall throttle body flash done along with 2 other recalls. Since then the truck does seem to drive smoother with maybe a little transmission gear seeking now and again. But the MPG has gone down. And I've been babying the throttle trying to keep it in V-4 as much as possble.

Took it back to the serivce shop that did the recalls. The service guy just said it's due to bad gas. Well 2 tanks later and no better. He needs the truck for an entore day to go thru it but won't give a loaner. I feel I should be averaging at least 16.. But closer to 18 at lowest. I have an 01 jeep with dana 44's and 35 in tires that gets almost this good of MPG.

Anyone else having this issue?

becker87 · February 25, 2014

What type of gas are you using? Which engine?

jmontz32 · February 25, 2014

2014 sierra 4 wheel drive with 2" level and drive it hard....still avg 20 mpg

Edited February 25, 2014 by 4x4offroad

dfwvtxman · February 25, 2014

Sorry .. it's the 5.3 And Chevron gas.

fondupot · February 25, 2014

I saw that too, I was also wondering if the DIC has an option for the average mph on the lowly SLT or is this Denali only?

I don't have it in my SLT.

Edited February 25, 2014 by fondupot

Dnt · February 25, 2014

Sorry .. it's the 5.3 And Chevron gas.

above results from my 2014 Crew Cab SLT Z71 4x4 5.3 3.42 with 20in all terrain tires......Set your DIC to the 25 mile range and reset it so you start with a fresh average, now go for a a minimum 25 mile drive watching the DIC mpg meter adjust your driving habits to produce great gas mileage and never return to your wicked fuel wasting ways now that you know what you were doing wrong. HEAL THY EVIL DEMON above results are from intense training watching the DIC meter. As Arnold would say Yuuooo can dooooo it

Edited February 25, 2014 by Dnt

dfwvtxman · February 25, 2014

IMAG1029.jpgIMAG1030.jpgIMAG1031.jpg

Set your DIC to the 25 mile range and reset it so you start with a fresh average, now go for a a minimum 25 mile drive watching the DIC mpg meter adjust your driving habits to produce great gas mileage and never return to your wicked fuel wasting ways now that you know what you were doing wrong. HEAL THY EVIL DEMON above results are from intense training watching the DIC meter. As Arnold would say Yuuooo can dooooo it

Go where and do what?? Speak in english man..lol

Dnt · February 25, 2014

Trying to remember how to do the setup. I have a Sierra but I think the Silvy is the same. On the steering wheel controls right hand side punch the < button that should open the display on the center of the dash between the tach and speedometer scroll to info and press the center button on the steering wheel right hand cluster this should get you into your selection screen now scroll to the fuel mileage one and once on there you can press the > button to be able to scroll between the 25 50 and 400 ranges.

Dnt · February 25, 2014

It is very interesting how a small change in driving habits can affect the fuel mileage tremendously just makes you very conscious of how you are moving your nearly 6000lbs of weight (Your truck with all your stuff in it) around. I still have to punch it now and then just for fun I left some long black streaks this morning out of the car wash sum bich will raise heck with the traction control turned off LOL but it has also been fun to see what I can get out of it as far as mpg.