2020 AT4 6.2L 10spd fuel economy

OnTheReel · March 31, 2020

1 hour ago, AdamAT4 said:

Dodge interior is a million times better, I shy'd away because I like the HD better, love the grill and front end on them. The sport looks better than the rest in the 1500. You can also get 3.92 gears and a larger fuel tank! 26L more than the GM. F150 has a 36L more than GM.

If the summer fuel economy dont improve I'll be trying out a new Ram, maybe factory order a 2021. I hear the Rebel TRX will be released this summer.

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I don’t imagine the TRX is going to be more efficient.

You’re running around on 87 octane winter gas and wondering why an engine with 11.5:1 compression is behaving like a dog? There has to be so much KR (knock ******) it probably runs like a 4.3. You don’t need 3.92s...

Likarok · March 31, 2020

35 minutes ago, AdamAT4 said:

Stupid comment, a big rig gets like 8mpg and sell based of fuel economy as you can go further and run cheaper. No one is expecting to get 40mpg or nothing like that. But if truck A gets 5 mpg more than truck B and does the exact same task then truck B will be more desired.

Plus many people say the 6.2 /10 speed is better than the 5.3 and my buddy has a 2017 5.3 and it's a pig for a half ton.

There's seriously something wrong with a 3/4 ton gas is better better mpg than a 1/2 ton.

This AT4 is going to cost me an extra $2500 per year vs Ford or Ram CC 6.5 box that does the exact same thing. I only bought the AT4 because everyone was like it's such a great truck and I didn't have to buy a level or new tires. My EcoBoost (CC 6.5 box with 3.55 and FX4/ tow pkg) was 20mpg easy with a level and 34x11 tires, I can't get this truck at 20mpg unless I'm driving 50mph.

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Well there you go!

AdamAT4 · March 31, 2020

I don’t imagine the TRX is going to be more efficient.

You’re running around on 87 octane winter gas and wondering why an engine with 11.5:1 compression is behaving like a dog? There has to be so much KR (knock ******) it probably runs like a 4.3. You don’t need 3.92s...

TRX will be way way less efficient but have 200 more hp and possibly raptor equivalent suspension. I probably wouldn't buy one as it would be over $100k in Canada. A raptor is $97k, and my AT4 was 78k.

No one looks at compression ratio when buying a truck, my buddy has a high county with a 6.2 and never used anything but 87, hes lifted on 37s so his fuel economy isnt worth looking at. the dealer also filled my truck with 87 and no one ever mentioned anything about 91. First truck I've heard of ever needing 91, a raptor makes 450 and runs perfectly on 87, a 520hp tune needs 91.

Truck dont knock, starts and drives fine. It idles near silent its awkwardly quiet.

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OnTheReel · March 31, 2020

You can run it on butane and probably not ping at idle, but at WOT it’s common to see these engines pull 6 degrees of timing or more on 87. If the knock sensors are doing their job you wouldn’t hear it, but you’re certainly not getting what you paid for in the 6.2. Plenty of people have posted data logs for the last generation that bear this out. It’s a performance engine. Cheaping out on fuel defeats the purpose of it, and is likely contributing to the poor fuel economy you are seeing too.

As far as the Raptor...define “runs fine” because the dyno charts tell the same octane story, but worse.

Stock tune 93 octane, 416hp

Stock tune 87 octane, 377hp

AdamAT4 · March 31, 2020

Interesting, I’d be surprised the knock sensor didn’t cause a CEL. or nothing like that would be mentioned by the dealer. I’d guarantee 95% of the 6.2s here are running on 87, probably only the camero or vette using 91.

Our dealer is a dud that should of been told, my jeep is a performance vehicle so I suspected it would need 91 anyway but at least the dealer said it needs at least 91.

I’m not worried about performance it is a truck after all, I only got it for the 10 speed and it was the only option I had without doing a factory order, all AT4 were 6.2 or diesel. If I wanted power I would of kept my Cummins with compounds and bought a Tacoma for a beater truck

OnTheReel · March 31, 2020

I’m not so sure about the 95% thing. I bet that a fair amount of people in the general population are running 87. But among enthusiasts here and on other groups, it’s about 95% the other way...

Anecdotal, small sample size, I know. Just the last poll I saw, and something to consider. Not all about performance either...

AdamAT4 · March 31, 2020

I’m not so sure about the 95% thing. I bet that a fair amount of people in the general population are running 87. But among enthusiasts here and on other groups, it’s about 95% the other way...

Anecdotal, small sample size, I know. Just the last poll I saw, and something to consider. Not all about performance either...

That pole is on a form we're probably many people know they need 91 as a red thread like this. Most part in Canada 91 is considerably more expensive than 87.

My uncle for example has a Denali with a 6.2 and he had no idea anyone even put 91 in pickup trucks he thought that was silly. But he like me always had a diesel I've only ever had one other gas truck and that was my EcoBoost everything else has been Duramax or Cummins.

If I would have done a little research prior to buying and knew my truck needed 91 I 100% would not have bought this truck. If our Winters weren't -40 I probably would have looked at the 3L Duramax for the fact that it's a straight 6 but I'm tired of waiting all day for my diesel to warm up

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OnTheReel · March 31, 2020

It is marked on the gas door and in the manual. As I said, I recognize that the enthusiast crowd will run premium in higher numbers than Joe Blow. But it does take somewhat of an enthusiast to buy a 6.2 in the first place. In the Denali it’s almost automatic to get the 6.2. But outside of that there’s a big upcharge, especially if you have to climb the “trim level ladder“ to get it. And unless that buyer really cares about having the extra power, it would be a non-starter.

Only other thing I can say is, as far as GM is concerned, premium is only recommended. As far as I’m concerned, it’s required. Even my 2016 5.3 would ping on 87 in certain scenarios so there is no way I’m using it in this truck. Of course there’s upsides and downsides either way. I’ll admit the fuel economy you make up with running premium probably won’t outweigh the added fuel cost. But the engine will be much happier.

CamGTP · March 31, 2020

These trucks/computer will never toss a knock code when running 87 octane because the engineers that design the calibration already know what is going to happen in the real world.

There is a reason why the calibrations have two different main timing tables. One with "normal" values and one that has anywhere from 5-15 degrees less timing depending on rpm and cylinder airmass. The computers can use a knock learn factor to interpolate the timing between the two tables when knock is or isn't present. As said, they computer is so fast at what it does you likely won't hear the ping inside the truck.

I have nothing else to really add to this thread lol.

Jav_eee · April 1, 2020

I have nothing else to really add to this thread lol.

Solid contribution regardless

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Jav_eee · April 1, 2020

Technically thats not true. This isn't a work horse motor, its more of a race horse motor. With a cast Aluminum block its not meant for heavy work, that would be the 6.0 l engine. I buy whatever floats my boat. Driving style ultimately dictates gas mileage. Having said that, if i can get better gas mileage, thats a bonus. The difference between my 2019 and 2016 is a lot, thats my concern. Glad yours does well for ya!

Nonsense. Just because it’s in sports cars too? I guess the Ford 5.0 isn’t a work horse either? Because I know a few ranchers who’d say otherwise.

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ArTurf · April 1, 2020

I don't have a AT4 but I'll throw in my experience with my 2020 Chevy HC, CC, 6.2, 6.5' bed, max tow pkg. trailer mirrors. I've been doing mostly highway travel with this truck since I bought it in Feb. Been making 300 mile trips, 60-70 mph and getting 21-22 mpg. I'm happy considering the power available. Part of me still wants the 3.0 Diesel though

Edited April 1, 2020 by ArTurf

steve841 · April 1, 2020

12 hours ago, CamGTP said:

These trucks/computer will never toss a knock code when running 87 octane because the engineers that design the calibration already know what is going to happen in the real world.

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.

Edited April 1, 2020 by steve841

Oh Canada · April 1, 2020

12 hours ago, Jav_eee said:

Nonsense. Just because it’s in sports cars too? I guess the Ford 5.0 isn’t a work horse either? Because I know a few ranchers who’d say otherwise.

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LOL, no, because of the design of the motor. Aluminum block is not as reliable as the cast iron block. Thats proven. The previous post mentioned that the 6.2 l motor was a work horse motor, and i pointed out that it wasn't meant to be the constant hauler, puller, etc, which it is not. A high compression aluminum block motor ultimately is not a work horse. Why do you think its not offered in the 2500's? Thats not to say it cant tow and haul here and there. I do that with mine.

Have a good day.

DirtyAndy · April 1, 2020

LOL, no, because of the design of the motor. Aluminum block is not as reliable as the cast iron block. Thats proven. The previous post mentioned that the 6.2 l motor was a work horse motor, and i pointed out that it wasn't meant to be the constant hauler, puller, etc, which it is not. A high compression aluminum block motor ultimately is not a work horse. Why do you think its not offered in the 2500's? Thats not to say it cant tow and haul here and there. I do that with mine.
Have a good day.

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