Active Fuel Management vs Dynamic Fuel Management Infographic

[Zane]

14 hours ago, Grumpy Bear said:

Zane in the second paragraph titled "Dynamic Fuel Management" there is a line stating the amount in percent that DFM is on over AFM and due to the glare I can not read it. What does it say please? Thank you. 

"During an industry-standard test schedule, the 2019 Silverado 2WD with the 5.3L and DFM operated with fewer than eight active cylinders more than 60 perfect of the time, a 9 perfect improvement over the comparably equipped 2019 model with AFM" 

[Z45]

On 8/11/2018 at 9:10 AM, Black02Silverado said:

It will be interesting to see how this operates.  I notice every time our 2016 Suburban goes into 4v mode. Makes a low rumble sound. Not from the exhaust either.  

That seems to be so with the 5.3L engine.  My 2017 Sierra Denali with 6.2L engine, I cannot tell when it goes into V4 mode, even when I am watching the display, can't feel or hear anything.  My 2015 was same, in 50,000 miles it never made any change, you would never know it had AFM.  Also, never used a drop of oil.   

Edited August 14, 2018 by elcamino

[David_L6]

I hate to think this but it appears that I have already purchased my last GM product. I'm 55 years old and I've owned 8 GM made vehicles in the time that I've been driving. Only one with AFM and it was the ONLY one that I had issues with. 2008 Silverado with 5.3. First was oil pump failure. Next was a collapsed lifter that also wiped out the camshaft. Next was a failed injector. I currently own a 2012 Silverado with a 6.2 and no AFM. No issues. Before the 2008 I had a 1999 Silverado with the 4.8 and no AFM . No issues.

 

NO thanks GM. No more of  your gimmicks for me. 

[Loco-diablo]

1 hour ago, elcamino said:

That seems to be so with the 5.3L engine.  My 2017 Sierra Denali with 6.2L engine, I cannot tell when it goes into V4 mode, even when I am watching the display, can't feel or hear anything.  My 2015 was same, in 50,000 miles it never made any change, you would never know it had AFM.  Also, never used a drop of oil.   

With my 2017 5.3. I can't tell when it goes into V4 mode. It's very smooth.

[Nargg]

I've had AFM in my last 2 GM trucks.  I've never noticed any weird noise or other problems at all.  I think those that do are trying to hard find problems rather than actually having problems.  I like that GM pushed this and that it does get better MPG.  (3+ MPG average over my previous non-AFM engine.)  Can't wait to see how well the new DFM works.

[Nargg]

2 hours ago, repairman54 said:

Range in my '11 Tahoe for the last 50k miles. Highway mpg dropped by 1 mpg. AFM issues are not worth 1 mpg in my book.

Everyone talks about issues, but nobody actually sees them.  Kinda funny huh?   

 

AFM/DFM is here to stay folks.  Get over it.

[Jsdirt]

Well Nargg, that depends on what your job is ...

 

 

[Loco Diablo]

I can’t believe V-8 drivers or V6 drivers put up with it, especially for the little gains. I tested mine every way possible barely got a mile a gallon with it on. Got out of it as soon as possible. Never going to have one.


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Don’t they have to meet gvmt regulations regarding MPG?
In order to meet those requirements, someone at GM came up with deactivating cylinders.


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[Jsdirt]

Great idea on paper ... but like most 21st Century designs, POORLY EXECUTED.

[amxguy1970]

3 hours ago, David_L6 said:

I hate to think this but it appears that I have already purchased my last GM product. I'm 55 years old and I've owned 8 GM made vehicles in the time that I've been driving. Only one with AFM and it was the ONLY one that I had issues with. 2008 Silverado with 5.3. First was oil pump failure. Next was a collapsed lifter that also wiped out the camshaft. Next was a failed injector. I currently own a 2012 Silverado with a 6.2 and no AFM. No issues. Before the 2008 I had a 1999 Silverado with the 4.8 and no AFM . No issues.

 

NO thanks GM. No more of  your gimmicks for me. 

1 truck out of 8 and you are that sour? Failure rates are in the 1% give or take range, if that sours you enough be prepared for some other issues with the other manufacturers, just have to pick your poison. To me that would be more reason to stay having a strong run of trucks.

35 minutes ago, Jsdirt said:

Great idea on paper ... but like most 21st Century designs, POORLY EXECUTED.

Yeah, 1% give or take failure rate over millions is far from poorly executed. When it adds 1mpg per vehicle on average and you take in to affect the others that 1 mpg brings to the table to the consumer, government, environmental impact and all others it is a very good technology...

 

Tyler

[Jsdirt]

1% ??   Oh, it's FAAAR more than that. Anyone who gave you that number must work in GM's PR department ...

[David_L6]

1 hour ago, amxguy1970 said:

1 truck out of 8 and you are that sour? Failure rates are in the 1% give or take range, if that sours you enough be prepared for some other issues with the other manufacturers, just have to pick your poison. To me that would be more reason to stay having a strong run of trucks.

Yeah, 1% give or take failure rate over millions is far from poorly executed. When it adds 1mpg per vehicle on average and you take in to affect the others that 1 mpg brings to the table to the consumer, government, environmental impact and all others it is a very good technology...

 

Tyler

No, that is 100%. One, truck had issues. The only one with AFM. 

[Grumpy Bear]

One of the motors Ford Trucks used between 1965 and 1972 was the 300 in line six. 283 lbs/ft @ 1,600 rpm but only 170 hp @ 3,800 rpm. (Actual run of the motor covered 1965-1996). They got 15 to 20 mpg but would pull down a house due to the steep 6.69 low gear (NP 435 transmission) and a 4.11 diff. 7,836 lbs./ft. in low gear!!! 

 

A 6.2 (460 lbs./ft.) with 8L90E (4.56 low gear) and a 3.73 gear gives 7824 in low but at 4,100 rpm before the show gets started. Don't think they come with 4K stall coverters. Mileage is about the same. 

 

50% more motor for the same grunt. Now there is some progress. All that really changed is the speed you can move down the highway. People are impatient. 

 

 

[Loco Diablo]

So folks here are talking about AFM related failures on trucks 10 years ago.

I’d like to hear about or see numbers on how the current L83 ecotec3 AFM engines are holding up?


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[Jsdirt]

I've heard of several with failing injectors right out of the gate, and this was several months back. All less than 3k miles, some less than 700 mi..

 

That's the joy of buying new - you don't really know how "great" a deal you got until you're well out of the warranty period.

Edited August 16, 2018 by Jsdirt