2014 GMC Sierra 1500 mpg

[Rawyzf]

Yes tires are E rated and they're sitting about 42psi per the tire shop. I have been running 85 octane I believe. Same thing I ran in my Canyon

 

You could try bumping that up to 45F/44R cold, might help a little as long as the ride doesn't get too harsh.

 

Also, not everyone will agree with me on this, I'd run higher octane if you can. Yes, the manual says you can run base grade, but I highly suggest trying premium (or even e85 if your truck is capable). In my opinion, the higher grade improved the drivability of the truck and MPGs. (e85 doesn't apply to higher mpgs, but way better drivability).

[dorkweed]

Just filled up my brand new 2016 in my signature. The "average" in the display read 22.0mpg and had driven 640 miles on the entire tank; no trailer towing on this tank of fuel. I "hand calculated the TRUE average MPG and it came out to 21.2mpg for this tank of fuel. Twas a mix of typical suburbia driving and 2 120 mile round trip highway jaunts. All stock except for the catch-can that I added................and just under 1200 miles on the clock now.

 

That said, your mileage is low. The lift, LT tires, and your driving habits are the cause. Mileage drops off at an increasing rate for every 1mph over 60mph. I'll see if'n I can dig up an article I read years ago about big rig drivers and such. Very enlightening.

[Juan_ID]

You could try bumping that up to 45F/44R cold, might help a little as long as the ride doesn't get too harsh.

 

Also, not everyone will agree with me on this, I'd run higher octane if you can. Yes, the manual says you can run base grade, but I highly suggest trying premium (or even e85 if your truck is capable). In my opinion, the higher grade improved the drivability of the truck and MPGs. (e85 doesn't apply to higher mpgs, but way better drivability).

Truck is e85 capable but if it won't increase mileage I doubt I'd try it. But what do you mean it increases "drivability"? I may have to try a few tanks of premium and see if the mpg increases (if any) offset the added fuel cost. I guess I just can't believe it's as low as it is currently, being it's not really lifted. I always thought the 4.10 and 4 speed combo of the canyon would suck on mpg, and while it wasn't the best I expected the Sierra to get at least what it got with the 3.42s and 6 speed. The canyon was leveled too and had stock size E rated a/t tires.

[Rawyzf]

Truck is e85 capable but if it won't increase mileage I doubt I'd try it. But what do you mean it increases "drivability"? I may have to try a few tanks of premium and see if the mpg increases (if any) offset the added fuel cost. I guess I just can't believe it's as low as it is currently, being it's not really lifted. I always thought the 4.10 and 4 speed combo of the canyon would suck on mpg, and while it wasn't the best I expected the Sierra to get at least what it got with the 3.42s and 6 speed. The canyon was leveled too and had stock size E rated a/t tires.

E85: This will indeed decrease you're mpg, probably 25% However, if the cost of e85 is 25% less than the cost of Regular, you win that battle. E85 is always more than 25% less than premium, which is why I almost always run it.

 

Now to the drivability comment: I noticed that the truck accelerated and drove with less effort (aka gas pedal) when running premium. Base grade seemed to hiccup or even feel sluggish on takeoffs or acceleration scenarios (passing, etc). I can almost guarantee that you will not get the $ back from running premium if you calculate the mpgs vs base fuel, but I also know you will enjoy driving your truck more.

 

I know I've gotten a bit off track, as I think you might have some other underlying issue getting only 13 mpgs, but these are some other thingsto think about.

 

Sent from my SM-G930V using Tapatalk

[Juan_ID]

Just filled up my brand new 2016 in my signature. The "average" in the display read 22.0mpg and had driven 640 miles on the entire tank; no trailer towing on this tank of fuel. I "hand calculated the TRUE average MPG and it came out to 21.2mpg for this tank of fuel. Twas a mix of typical suburbia driving and 2 120 mile round trip highway jaunts. All stock except for the catch-can that I added................and just under 1200 miles on the clock now.

 

That said, your mileage is low. The lift, LT tires, and your driving habits are the cause. Mileage drops off at an increasing rate for every 1mph over 60mph. I'll see if'n I can dig up an article I read years ago about big rig drivers and such. Very enlightening.

I have no doubt my driving is a factor, but at the same time I'm not going to drive 60-65 when the speed limit is 80. I could be better about not having such a heavy foot but I still expected what I got out of the canyon or close to it. I guess it might just be what it is. If you find that article please post it, I wouldn't mind reading it

[dorkweed]

http://cumminsengines.com/uploads/docs/Secrets%20of%20Better%20Fuel%20Economy_whitepaper.pdf

 

 

Here's that article I told you about. I'm coming from the diesel world; having driven Dodge/Cummins trucks since '97, but the principles still apply to gassers. Enjoy.