2020 AT4 6.2L 10spd fuel economy

Oh Canada · April 1, 2020

33 minutes ago, DirtyAndy said:

C’mon man. I conceded to your point. No need to keep rubbing it in! Lol

Crap, sorry DirtyAndy. Not my intention. Have a good one. Cheers

DirtyAndy · April 1, 2020

I was joking, man. Lol.

joshuapchase · April 1, 2020

On 3/27/2020 at 2:45 PM, AdamAT4 said:

Can someone tell me if it gets better? I knew GM isn't great on fuel in gas engines, duramax is probably best in HD.

I've heard the 6.2 with 10 speed was decent so I test drove and liked it. I didn't want a 3.23 rear end but the 10 speed has a lower first so I figured GM engineers knew what they were doing.

Turns out this thing is a pig, worse half ton I've ever used. I have a 17 power wagon.. big ole 3/4 ton gas 6.4L and 6 speed junk transmission and they are very similar in fuel economy. This AT4 is so bad I get better economy with my F150 EcoBoost with 6" left and 35" 10 ply mud tires.

If it does get better I'll keep it if not I'll go back to the dealer and beg for my old truck back.

Dead flat highway avg is 16-17L/100 or 13 -14 mpg I could get that in my ram towing a trailer.

Please tell me life gets better, I really do love my AT4

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I sold my 2019 GMC Sierra AT4 with the 6.2... bought a 202 Silverado with the Duramax... NIGHT and DAY difference with fuel economy... don't miss the pig at all...

CamGTP · April 1, 2020

9 hours ago, steve841 said:

Speaking from experience. I beg to differ.

I ran 87 in my 6.2 and it knocked. Not crazy, but noticeably.

Ended up mixing premium with mid grade.

My point was that it doesn't toss a check engine code. All it's going to do it ****** the ignition timing to reduce the knock. Most people won't hear it or even know what to listen for. That soccer mom that fills it up with 87 isn't going to have a clue what it going on.

Oh Canada · April 1, 2020

On 3/27/2020 at 4:45 PM, AdamAT4 said:

Can someone tell me if it gets better? I knew GM isn't great on fuel in gas engines, duramax is probably best in HD.

I've heard the 6.2 with 10 speed was decent so I test drove and liked it. I didn't want a 3.23 rear end but the 10 speed has a lower first so I figured GM engineers knew what they were doing.

Turns out this thing is a pig, worse half ton I've ever used. I have a 17 power wagon.. big ole 3/4 ton gas 6.4L and 6 speed junk transmission and they are very similar in fuel economy. This AT4 is so bad I get better economy with my F150 EcoBoost with 6" left and 35" 10 ply mud tires.

If it does get better I'll keep it if not I'll go back to the dealer and beg for my old truck back.

Dead flat highway avg is 16-17L/100 or 13 -14 mpg I could get that in my ram towing a trailer.

Please tell me life gets better, I really do love my AT4

Sent from my SM-N975W using Tapatalk

Just noticed the different camera options on your screen over my 19.

Also noticed the nice rides you have.

Is that an Srt4 Jeep? You must live in a similar climate to me, lots of snow.

AdamAT4 · April 1, 2020

Just noticed the different camera options on your screen over my 19.
Also noticed the nice rides you have.
Is that an Srt4 Jeep? You must live in a similar climate to me, lots of snow.

Yep 2020 Jeep SRT8 and 2020 AT4

Snow is my favorite

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Hydro4acid · April 2, 2020

Also something to note: in Canada, you will see that 87 octane can have up to 10% ethanol. Ethanol has a lower energy value that other gasoline additives. so vs 91, you will see timing and less energy in each molecule of gas, therefore worse mileage. However, the difference of energy between 87 and 91 fuel does not make up for the difference in 87 octane cost vs 91 octane gas.

I run 91 in my 6.2L and get 10-11L/100km on the higwhway (i think this is like 22-24mpg) and i think thats great for the truck where everyone is calling the 6.2L a pig. But if u floor it and drive it like so in town, its gonna let you know its thirsty.

The 16-17 that this guy is showing on his at4...who knows, maybe thats due to snowmobile and no cover, along with gas type. Not sure. May be other factors at play.

steve841 · April 4, 2020

The 6.2 is a beast .. but you'll never see numbers like this ... I was just hitting the off ramp after cruise set at 78mph

Jav_eee · April 4, 2020

The 6.2 is a beast .. but you'll never see numbers like this ... I was just hitting the off ramp after cruise set at 78mph

5.3?

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steve841 · April 4, 2020

30 minutes ago, Jav_eee said:

5.3?

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3.0L turbo diesel

AdamAT4 · April 5, 2020

1 hour ago, steve841 said:

3.0L turbo diesel

Hows the diesel working out? have heard a few issues on them. i like the fact that its a straight 6, but if i bought one i would miss my cummins.

I sold my diesel as its so cold here we can never them warm and the GM's are too hard to delete so i don't want to be stranded from failed DEF

AdamAT4 · April 5, 2020

Got to test mine today with 91. I took 3 gas cans and went till i ran out.

with the 91 the truck still seems to drive them same but i have not hammered on it yet and only drove like an old lady on the highway to see how low i can get it.

Currently at 12.0 L/100km or 19.6 mpg ... thats on highway with the with the economy range thing set to 50km/30 miles driving 65mph / 105kph on dead flat road.

steve841 · April 5, 2020

18 minutes ago, AdamAT4 said:

Hows the diesel working out? have heard a few issues on them. i like the fact that its a straight 6, but if i bought one i would miss my cummins.

I sold my diesel as its so cold here we can never them warm and the GM's are too hard to delete so i don't want to be stranded from failed DEF

Well, only 104 miles on it. But, I absolutely love it. From my 6.2L to this is just awesome. I hope there's no headaches.

I used to get 17 mpg at best in "real" driving on the 6.2-usually closer to 15. Now with the diesel, 25 mpg today all highway at 78 mph. That's over 40% increase in mileage.

Supercup · April 5, 2020

I have 4,806 miles on my 2019 AT4 - average from day 1 is 14.2 MPG - I have attached 4 photos - trip 2 - which I have not reset since new, trip 1, which is mix of street and freeway driving. 50 mi - screen showing last 50 miles and then showing what that looks like when switched ot the last 400 miles, as you can see big change from 50-400 - bringing me closer to my "overall" average of 14.2 mpg. Driving has been a mix of around town and trips to the lake - i don't comute in it, gas tank is just to small, as I drive 150 miles 4 days a week. I drive faster than most on freeway and get up to speed quickly getting on. Around town I drive respectfully - so easier on the pedal. Overall I am fine with 14.2 given how I drive - was hoping for 15+.

I had a 2014 Raptor with 6.2 before and I got 12-14 mpg pending on driving conditions and 13.1 mpg over 88,000 miles. Most of the miles were commuting from OC to San Diego, 4 days per week and driving to desert and lake. I replaced the stock 36 gallon tank with a transfer flow 50 gallon tank - which was great (link:https://www.transferflow.com/shop/replacement-fuel-tanks ), wish they would make a big tank for our trucks

When gas is $4 per gallon i figured i was cheaper to have a Golf R for commuting and truck for the weekends gas savings were greater than the added cost of the R. Now with gas at $2.75 for 91, I will drive the the truck more...

As I get more miles I expect i will see better mileage - if you are looking for mileage - V8 trucks are not the way to go! I have stock tires, with level kit for front so the lift does not help either.

Edited April 5, 2020 by Supercup

ElmoTheRed · July 30, 2020

After reading these posts I am a little disappointed in my AT4. Just purchased it and love it except for the mpg. First tank (from the dealer who knows what they put in it) got 11.1 mpg. That was mostly city driving but I did buy it about 50 miles from home so the first trip was on an interstate and only saw about 17 mpg at best.

I filled up with the second tank and I am seeing over 12 mpg but it is only 87 octane and only have less than a hundred in it.

I am hoping on three things that higher octane will yield higher mpg, a cover will help and that the break in period will also increase the mpg.

I thought i did enough research but didn't realize that the mpg numbers were based on 93 octane. If I would have known that I would have waited until a diesel was available because the difference between diesel and 93 octane is negligible where I am.

I am blown away that with the AT4 lift causes so much loss of mpg vs a Denali. (But they look so much better)