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Posted (edited)

I was averaging 19 MPG and a best of 20.5 MPG with a mix of city and highway... All of a sudden I'm only averaging 17.5 MPG to 17.9 MPG. I have about 14,500 Miles on my rig and I haven't changed anything. I noticed this right before my last oil change and my tire pressure dropped about 5lbs. I was expecting the fuel economy to go back up after they put air in my tires, but that doesn't seem to be it. Any thoughts? Was I just breaking in and now this is my true mileage per gallon? I went a little over on my oil change, but I wouldn't think that would affect it...? Thoughts?

Edited by Donovan514
Posted

A tank of E85 every so often is great for cleaning your engine.

 

Much more power, but MPG SUCKS. You lose about 28%.

Posted (edited)

Where are you located? This happens every year here in MI. The winter blend gas can easily rob you of 1-2 MPG. Also, as the ambient temp drops, it takes longer for your truck to reach normal operating temp. The main one being your tranny fluid temp. The colder it gets, the longer it takes, and there is a direct correlation between your engine staying in V8, until the tranny temp reaches the certain level.

 

I've been through two winters already, and the colder the outside temp, the higher your tranny temp needs to be before it will go in V4 more. During the warm weather it will switch to V4 as soon as you are in 3rd gear or higher. When temps start closing in on the freezing mark, your tranny temp will need to be in the mid 90º's F. When temps drop to around the Zero mark, your tranny temp will need to be up in the 113ºish F range before it will go into V4, and this can take 5-8 miles or so. When temps drop to -40º F, it can take 10-15 miles of rural highway driving before the tranny temp is warm enough.

 

Not to mention, your engine temp also needs to be up to NOT for best mileage. If you remote start your vehicle in the colder months, this also robs from your gas mileage a great deal, however you may gain a little back driving as things will be up to temp faster. Longer trips will see the most gain, shorter trips in the winter will be just like a full time V8.

 

I drive 28 miles one way to work. Guys that live within a few miles will never experience the full potential of what these trucks can do in the MPG dept. Of course they don't have the high mileage on their truck or have to buy as much gas. I'll take the country living, myself.

 

These trucks can still get good mileage on rural highways in the cold winter, but not until things are up to temp. If your drive is short enough that it don't get up to temp, not so much. I guess it all weighs out in the end.

 

I get an average of 21.5-22.5 MPG in moderate temps, that can easily drop 3-4 MPG during the extreme cold months of the winter. On Star remote starts before leaving work in the winter, playing in the snow, living 2-1/2 miles from the nearest pavement, last road in the county to get plowed out, etc,. IIRC, my worst tank MPG was 17.1 on the DIC, and hand calculated at 16.9, in the coldest and snowiest winter.

Edited by Ventilator
  • 2 weeks later...
Posted (edited)

I'm living in vegas and I'm getting some terrible fuel economy lately.

I've owned the truck for a little over a year now with 10k miles and my average is about 14 mpg. I've driven atleast 2k miles on freeway going from state to state but I'm definitely doing city/highway mix of driving. Admittedly I can probably say my day to day driving is atleast 75% city but my fuel economy is dropping to about a 13mpg average per tank. I don't think I have a leadfoot or anything but I don't know what the problem is.

 

(possible 3.08 gears being the problem or the a/t tires that came with the lt z71. I have no clue)

Edited by snowbrdd
Posted

Fuel prices are dropping regularly here in central Indiana...

 

With 9000 miles on the truck, 70% are highway miles. We are averaging 19.7 mpg.

 

Cannot complain about this for a long bed 4X4 partially loaded.

Posted

Anyone run e85 full time? If so, just wondering your mpgs and truck info.

 

Sent from Tapatalk App - Samsung S6

Posted

Kind of late but hey I purchased a certified 2014 Silverado LTZ 4x4 on 11/20/15, drove over 600miles the next day on the interstate (flat road) and could not get the AFM to engage at all over speeds of 58 mph and the dealer says that is normal. 16.2 mpg and believe me I am not happy with this truck . I've already block payment and started repair or take it back proceedings. I don't really care which one.

Posted

Kind of late but hey I purchased a certified 2014 Silverado LTZ 4x4 on 11/20/15, drove over 600miles the next day on the interstate (flat road) and could not get the AFM to engage at all over speeds of 58 mph and the dealer says that is normal. 16.2 mpg and believe me I am not happy with this truck . I've already block payment and started repair or take it back proceedings. I don't really care which one.

Posted

I got my last 25 average to be 8 MPG. Combination of idling due to the snow storm we just had in SE Michigan, and also some messing around in the snow :-)

Posted

Anyone run e85 full time? If so, just wondering your mpgs and truck info.

 

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I did for about 7-8 months, typically averaged 14-15 mpg mix driving but mostly open road and highway. Truck always drove great on it other than the mpg loss. I drive a 2014 dbl cab z71 5.3. Since regular gas has come down and the spread around here is only 20 cents I've been experimenting with ethanol percentages and using more 87. But even on 87 I'll only manage to get into the 18's mpg. I do have larger LT AT tires though.

  • Like 1
Posted

I did for about 7-8 months, typically averaged 14-15 mpg mix driving but mostly open road and highway. Truck always drove great on it other than the mpg loss. I drive a 2014 dbl cab z71 5.3. Since regular gas has come down and the spread around here is only 20 cents I've been experimenting with ethanol percentages and using more 87. But even on 87 I'll only manage to get into the 18's mpg. I do have larger LT AT tires though.

Good info, thanks.

 

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Posted

I believe from my limited experience with this setup that in real world settings these trucks will never see what they are advertised and prompted to do. They told me that on the interstate they would run in V4 mode at speed limit, well I know of no interstate highway that it is even safe to run 58 mph continues for this thing to work. The worst readings in mpg 25 so far is 13.2. So far real world is between 15 & 16 mpg overall average. I could do this good with a Dodge. Good bye Chevy truck.

Posted

I believe from my limited experience with this setup that in real world settings these trucks will never see what they are advertised and prompted to do. They told me that on the interstate they would run in V4 mode at speed limit, well I know of no interstate highway that it is even safe to run 58 mph continues for this thing to work. The worst readings in mpg 25 so far is 13.2. So far real world is between 15 & 16 mpg overall average. I could do this good with a Dodge. Good bye Chevy truck.

So is the loss you are going to take trading it in going to make up for your gas mileage loss? Something is up with your truck or your driving habits are causing such bad gas mileage. If you selling dealer can not fix it then take it some where else.

  • Like 1
Posted

I cant tell you guys anything about your mileage but in my truck doing about 90% city driving, I am averaging almost 16 mpg which is exactly what the sticker states I should get in the city.

Posted

​I didn't say anything about trading, I stopped payment on the 14K down payment and said fix it or keep it don't care which one.

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