2014+ Gas Mileage (MPG) Topic

[BringTheRain403]

What are you towing?

 

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[timmyltr]

Im surprised about the MPG posted, i expected better than that! certainly not enough to justify switching my 11 denali for a 14 denali 5,3! my 6.2 average 18 mpg gallon on highway, i thought it sucks but really not that bad after all!

[White14]

Towing nothing

 

 

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[BringTheRain403]

Oh wait you have the jacked up white Silverado with 4.56 gears. That makes more sense now lol

 

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[White14]

Correct

 

 

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[2014Z71LTZ]

Seen a lot of talk on here about MPG going south after the recall update, i noticed the same thing but after thinking about this some more maybe its just more of the cold weather bad MPG. I got my recall done early January about the same time as the temps have really falling off in most of the country. I drive the same drive everyday one way to work 15 miles. In the summer months I was getting 20 MPG all the time, once the colder fall months came around I was is getting about 18 MPG, now since it has been colder than hell (beginning of January) I'm only getting 16 MPG. Also with the temp never going above 20 around here for the last month, on my 15 mile trip the water temp won't hit the 210' mark until I am almost to the end of the trip. I really think the crappy MPG is just due to the extreme cold.

[redwngr]

Im surprised about the MPG posted, i expected better than that! certainly not enough to justify switching my 11 denali for a 14 denali 5,3! my 6.2 average 18 mpg gallon on highway, i thought it sucks but really not that bad after all!

Take one for a test run and make the comparison the same way you check your current ride.

[timmyltr]

Take one for a test run and make the comparison the same way you check your current ride.

i did with a 14 slt 5,3, i saw 1-2MPG better. But way down on power!! The new Denali didnt got me all excited anyway. I think ill stick with my 10 denali for another year and then ill take another look.

[pm26]

Can't you request that they reset the system to the previous settings, i.e. undo the update (at least temporarily) and then see if the mileage improves? At least you would eliminate this as the root cuase if something else is causing it.

 

I have hard time understanding how can some small software update severely reduce the fuel economy unless someone really messed with the fuel mapping and ignition timing advance.

Edited February 2, 2014 by pm26

[Ton J]

They had a recall on fuel pump calibration that why they had the first update 13330. Then the 14008 update fix remote start problem which caused the exhaust to over heat and the they cancelled the 13330 updated and replaced it with a new updated. I Asked my GM dealer about and they just go with what GM Tech tells them. I told them its my truck I would like a better understanding of these updates seeing that GM really not explaining them to much.

[Ton J]

Can't you request that they reset the system to the previous settings, i.e. undo the update (at least temporarily) and then see if the mileage improves? At least you would eliminate this as the root cuase if something else is causing it.

 

I have hard time understanding how can some small software update severely reduce the fuel economy unless someone really messed with the fuel mapping and ignition timing advance.

Safety Hazard because of the fire from over heating. so they won't roll back the updates

[Ton J]

 

This is exactly what the hell happened to me, no joke when from 16-18 to 11-13 after my freaking updates. I'm going in Saturday for my rear window recall and I am going to raise hell.

What dealership?

[zback]

Oh wait you have the jacked up white Silverado with 4.56 gears. That makes more sense now lol Sent from my SCH-I535 using Tapatalk 2

 

 

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I don't understand how you think you would be getting great fuel milelage with those mods you have?

[BringTheRain403]

They had a recall on fuel pump calibration that why they had the first update 13330. Then the 14008 update fix remote start problem which caused the exhaust to over heat and the they cancelled the 13330 updated and replaced it with a new updated. I Asked my GM dealer about and they just go with what GM Tech tells them. I told them its my truck I would like a better understanding of these updates seeing that GM really not explaining them to much.

 

The 14008 recall incorporated the 13330 recall into it. It's just software updates. It's kind of like when windows does one big service pack instead of installing a bunch of little software patches they do one big one...

 

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[Ton J]

I get the vapor thing, but it still doesn't explain why my 2012 Silverado got better gas mileage and I getting 18-19 in it summer and winter. And it switched from V8 to 4.

Sound everybody just wants to just to it GM word on it.

Edited February 3, 2014 by Ton J