2014+ Gas Mileage (MPG) Topic

[strike1st]

So with our temp swing over the last week...City driving I was up around 13.5 mpg but the temps were in the 30's and low 40's. the last couple days have been back down in the low 20's...same route driving the same way...just like a hamster on his wheel...back around 10.5 - 11.

 

Because of work I haven't made into my dealer. via phone they're saying that's not right (they're in the "city") so they see a lot of "city" drivers in these trucks. I spoke with GM Customer Service via a chat window...she said wait until 2000 miles because your truck isn't broke in yet. When I asked why then the owners manual says 500 miles was break in I got no answer. She also said nothing is wrong with my truck because 13 is close to 16 (I'm assuming GM has adopted "common core" math). When I asked if 10.5-11 was close to 16 she told me no it wasn't.

 

So I'm assuming I should take the truck in now since GM considers that there is something not right now...but when temps go up everything will be "normal".

[Audioi]

This was my 500 miles drive home from the dealer. Very impressed

 

 

Ok stupid question, how do I get to this screen?

[Full Lock]

Ok stupid question, how do I get to this screen?

 

Go to your info screen and it's in there. If it's not, then you have to go into the setting in the DIC and you can select what screens you want to display and what screens you don't.

[Audioi]

Never thought of that, I bet its turned off. Thanks!

[Full Lock]

I figured it would be safer to run 93oct since these engines run a pretty high 11.5 compression ratio.

 

So, I just filled up with 93oct and so far I'm seeing a 2.5mpg-3mpg drop over the 87oct I was running before. Anyone else notice this?

 

FYI the outside temps have been about the same

 

Just double checked the owners manual and sure enough, it says to use 91 or higher with the 6.2L's. Dealer put in 87 so I though that would be ok but I guess not. Goes to show ya, dealers are idiots.... We'll most of them

Edited March 26, 2014 by Full Lock

[fondupot]

I figured it would be safer to run 93oct since these engines run a pretty high 11.5 compression ratio.

 

So, I just filled up with 93oct and so far I'm seeing a 2.5mpg-3mpg drop over the 87oct I was running before. Anyone else notice this?

 

FYI the outside temps have been about the same

 

Just double checked the owners manual and sure enough, it says to use 91 or higher with the 6.2L's. Dealer put in 87 so I though that would be ok but I guess not. Goes to show ya, dealers are idiots.... We'll most of them

 

the higher octane will be worse in colder temps. So just use the recommend 87 until it starts to warm up.

[Full Lock]

Yeah I was thinking that but the manual says no less than 91 for the 6.2s. I might put some 87 in it for my drive back out to colorado though cause I was liking 20mpg+

Edited March 26, 2014 by Full Lock

[Dnt]

Yeah I was thinking that but the manual says no less than 91 for the 6.2s. I might put some 87 in it for my drive back out to colorado though cause I was liking 20mpg+

Are the 6.2 engines Flex Fuel like the 5.3?

[Full Lock]

Are the 6.2 engines Flex Fuel like the 5.3?

No

Edited March 27, 2014 by Full Lock

[bigsapper]

 

Are the 6.2 engines Flex Fuel like the 5.3?

 

 

yes

 

Pretty sure that's wrong. Everyone that I'm aware of with a 6.2 in a 2014 Silverado/Sierra, none are flex fuel.

 

Do you have a yellow gas cap?

Edited March 27, 2014 by bigsapper

[Full Lock]

Pretty sure that's wrong. Everyone that I'm aware of with a 6.2 in a 2014 Silverado/Sierra, none are flex fuel. Do you have a yellow gas cap?

Woops you are correct its just the 4.3 and 5.3 that are flex fuel compatible.

[KARNUT]

Man that's just not right, 5.3 on flex fuel is 380HP, 6.2 cant burn it, and you have to run premium gas. Some one going to tune the 5.3 on flex right by a 6.2.

[z28evans]

2014 GMC Sierra 5.3 4wd Last week I was driving through Big Bend park here in Texas. Without trying I realized I got 30.9 mpg over a 25 mile period:

 

 

*in the park the speed limit is 45mph for miles on end, which probably had something to do with it. Thought it was interesting enough to share.

 

James

[bloudie]

I was in south Carolina with my 2014 6.2 with 3.73 rear and 20" wheels with stock tires.....tire pressure was 37 lbs. gas used was pump 87 octane.... was 40-50 farenheit outside air temp. I was pulling a tiny 4x8 utility trailer with a 1000lbs. or so of tools. truck also has a vinyl bed cover. truck has 1000 miles on it.

 

32 m.p.h. = exactly 28 mpg [go to 35 m.p.h. to get truck in 5th gear and then slow down to 32 m.p.h.on cruise control.....truck sometimes shifts to 4th]

40 m.p.h. = over 25 mpg 6th gear

50-55 m.p.h.= over 23 mpg 6th gear

 

towing a double axle 28' enclosed car hauler from Georgia ,, radial tires 80 lbs of air in 16" radial tires [under 6000lbs. estimated weight.and added cargo]

35-40m.p.h. = 17 mpg 6th gear

45 m.p.h. = 14mpg 5th gear

50 m.ph. = 12-13 mpg 5th gear

 

these numbers were accomplished with perfect tire pressure, ordinary pump gas, NO WIND CONDITIONS, 6.2 motor in a double cab 2wd., ltz with no extra options except block heater, cargo lights and tie downs, bed rug, tonneau cover, 350lb. driver. road must be perfectly flat. [rte 17, just south of Charlestown s.c.] I think this is chevy's lightest truck with the 6.2.....

the only difference between the 6.2 and the 5.3 is bore size and a little more compression

[bigsapper]

Just got done with a little trip east running on I-20. About 18mpg on the highway with E85.

 

5.3L, 3.42, RCSB. I can live with that.