Crappy gas mileage in a 6.2l with the ac on?

[Brian Swaser]

I picked up a 2012 silverado with the 6.2l last Friday 9/20/19. It had a full tank of gas. I drove about 40 miles with it, having the ac on most of the time. After I had gone 40 miles, and the gauge reading over a 1/8 burned already. The topped off the tank. 5.778 gallons is what it took after 40 miles. Is this something I can expect, with the ac on, in the future? Thanks for any info. I WAS NEXT TO THE SALESMAN WHEN HE FILLED THE TANK. IF YOU CAN'T ADDRESS THE AC QUESTION DIRECTLY, PLEASE MOVE ON. 

Edited September 24, 2019 by Brian Swaser
Lack of info on the original post

[RyanbabZ71]

What type of fuel? Was it filled with E85 by chance? It will definitely go down faster with E85. Lucky to get 11 mpg with my old 2010 6.2


Ryan B.

[damnthetorpedoes]

Also possible that it had some miles on that tank before you took delivery and wasn't completely full. 

[CamGTP]

Perhaps the gas gauge isn't that accurate and it wasn't totally full?

 

If you think about it, 5.7 gallons is basically 1/4 tank because they only hold 26 gallons. That 5.7 gallons used should have put the needle just over the 3/4 full mark and not only down 1/8th of a tank.

 

The information display in the cluster should have both a fuel/gallons used and a instant fuel mileage display. I'd reset the fuel used and be watching the instant fuel mileage to see what it's showing.

[muddkatt]

Chances are that the tank wasn't "really" full. GM vehicles are known to ride on full for a long time before beginning to move the gauge. Every one I have ever owned would drop from 3/4 to 1/4 in just a few miles (about 50). Then they seem to be fairly accurate from 1/4 on down to E.

 

Since the truck is new to you, were you driving it hard? Nothing wrong with playing with the new toy, but fuel mileage will be in the 8-9MPG range when you play or pull trailers.

Edited September 24, 2019 by muddkatt

[riverbanks]

1 hour ago, Brian Swaser said:

I picked up a 2012 silverado with the 6.2l last Friday 9/20/19. It had a full tank of gas. I drove about 40 miles with it, having the ac on most of the time. After I had gone 40 miles, and the gauge reading over a 1/8 burned already. The topped off the tank. 5.778 gallons is what it took after 40 miles. Is this something I can expect, with the ac on, in the future? Thanks for any info. I WAS NEXT TO THE SALESMAN WHEN HE FILLED THE TANK. IF YOU CAN'T ADDRESS THE AC QUESTION DIRECTLY, PLEASE MOVE ON. 

You can move on too

[Brian Swaser]

27 minutes ago, riverbanks said:

You can move on too

Take your own advice. 

[riverbanks]

Go buy a kia

[CamGTP]

Hey mister edit your post guyyyyyyyyyyyyy, don't be a prick when you didn't include that information to begin with.

 

Having the AC on don't really mean shit anymore, not with these newer trucks and compressors. You may take a 1-2mpg hit max. I didn't lose any fuel mileage on the open road with the AC on.

 

If you truly are only getting 7-9mpg, something else is wrong.

[TXGREEK]

It’s a 2012, intake needs cleaning along with new plugs and cables. Run Amsoil 100% Synthetic in everything and not that misleading BS Full Synthetic.

[muddkatt]

There is nothing like waking up in the morning and having my first cup of coffee . I check out GM-Trucks forum first thing and find is that the new guy has edited his post from last night. At first his edit ticks me off, until I see that Ryan is one of the ones he is telling to "IF YOU CAN'T ADDRESS THE AC QUESTION DIRECTLY, PLEASE MOVE ON."   Now I have a grin on my face and wonder how long this guy is going to be on this forum. Nothing like pissing everyone off  and telling us how we should answer a question, INCLUDING the mods in your first 2 post.

[RyanbabZ71]

If you were standing next to him what fuel did he put in your truck? 87? 93? This is a serious question and can play in MPG as the 6.2 is recommended to run on 93.


Ryan B.

[redvett]

Does the truck have original size tires? Larger tires will decrease fuel economy, in fact more aggressive tires will also. 

[intheburbs]

It's a 6.2L truck with 400 hp, not a Prius.  Running the A/C has nothing to do with it.  You're going to get crappy mileage.  Period.  Bonus points because premium is recommended.

 

My Denali gets about 12 MPG around town.  When I floor the throttle, I swear I can see the gas needle moving.  If I try really hard, set the cruise at 65, with a tail wind, maybe it'll get me 15-16 mpg on the highway.

 

But you know what?  I don't care.  It's a blast to drive and every time I stomp the throttle it puts a big, stupid smile on my face.

 

Only complaint is the range.  At least my Suburban has a 39-gallon tank, so I still have a range of 500+ miles.  With only 26 gallons in the Denali, I'm lucky to get 300 miles out of a tank.

Edited September 24, 2019 by intheburbs

[Jak Conrad]

Ok, I guess I need to stop stressing about averaging 16-18 on my '04 Burb. :D