While I resent being labeled as an idiot, I accept your apology. The point of my post was that I'm not hearing complaints about GM V8 engines in trucks with AFM having oil consumption problems in this part of the country and I was wondering about the climate and driving styles interacting with the AFM contributing to the excessive oil consumption elsewhere in the country.
GM DOD/AFM Interesting Oil Observations
- Thread starter tony1679
- Start date
- Status
MolaKule
Staff member
Originally Posted By: Fredian_Obsid
Great Post! First time for me to hear this issue and it helps me find the answers to my question. http://www.hamburgtradinghouse.com/
Suspicious site alert came up on your link!
Great Post! First time for me to hear this issue and it helps me find the answers to my question. http://www.hamburgtradinghouse.com/
Suspicious site alert came up on your link!
Originally Posted By: Volvohead
Often, the reality is between the extremes.
Can we just agree that there were some people having problems with the early AFM engines, but not so many as to constitute a major issue?
Besides, to the extent some people were having a problem, it has, for the most part, been addressed by GM with production revisions. The incidence of internet complaints about AFM has dramatically fallen off since '10.
I agree. This was topic was information to help those in the "minority" having these problems. I also agree about '10 and newer vehicles not having as many problems.
Often, the reality is between the extremes.
Can we just agree that there were some people having problems with the early AFM engines, but not so many as to constitute a major issue?
Besides, to the extent some people were having a problem, it has, for the most part, been addressed by GM with production revisions. The incidence of internet complaints about AFM has dramatically fallen off since '10.
I agree. This was topic was information to help those in the "minority" having these problems. I also agree about '10 and newer vehicles not having as many problems.
Originally Posted By: 46Harry
While I resent being labeled as an idiot, I accept your apology. The point of my post was that I'm not hearing complaints about GM V8 engines in trucks with AFM having oil consumption problems in this part of the country and I was wondering about the climate and driving styles interacting with the AFM contributing to the excessive oil consumption elsewhere in the country.
I think the problem has little to do with climate, or driving style for that matter, but more the driving environment.
In case nobody is aware, GM programmed AFM (at least in 2008) to cycle every ten minutes to eliminate a stale charge IF AFM could stay activated for that long. So the maximum cycle is ten minutes in 4cyl mode, one full minute in 8cyl mode. Obviously this rarely happens in most scenarios, but is common in the great plains on the highway.
My observations were that I lost the most oil when AFM was active for the longest amount of time (the "maximum cycle"). Frequent cycling is a close second for oil loss (8-4-8-4-8-4-8 several times within a minute).
Maybe that answers the question.
While I resent being labeled as an idiot, I accept your apology. The point of my post was that I'm not hearing complaints about GM V8 engines in trucks with AFM having oil consumption problems in this part of the country and I was wondering about the climate and driving styles interacting with the AFM contributing to the excessive oil consumption elsewhere in the country.
I think the problem has little to do with climate, or driving style for that matter, but more the driving environment.
In case nobody is aware, GM programmed AFM (at least in 2008) to cycle every ten minutes to eliminate a stale charge IF AFM could stay activated for that long. So the maximum cycle is ten minutes in 4cyl mode, one full minute in 8cyl mode. Obviously this rarely happens in most scenarios, but is common in the great plains on the highway.
My observations were that I lost the most oil when AFM was active for the longest amount of time (the "maximum cycle"). Frequent cycling is a close second for oil loss (8-4-8-4-8-4-8 several times within a minute).
Maybe that answers the question.
Originally Posted By: Shark
Originally Posted By: A_Harman
How lean is your lean cruise? Do you have wideband O2 sensors on it?
16.3:1 at 40mph and above, below about 1/2 throttle. There was a wide band in while tuning. In Australia GM builds this into the tune.
Sounds reasonable. I've been thinking about putting in a tune via HP Tuner to get lean cruise on the highway. I was going to tune it to 15.8, but it seems like a little more is possible. Have you noticed any misfiring or weak throttle response?
Originally Posted By: A_Harman
How lean is your lean cruise? Do you have wideband O2 sensors on it?
16.3:1 at 40mph and above, below about 1/2 throttle. There was a wide band in while tuning. In Australia GM builds this into the tune.
Sounds reasonable. I've been thinking about putting in a tune via HP Tuner to get lean cruise on the highway. I was going to tune it to 15.8, but it seems like a little more is possible. Have you noticed any misfiring or weak throttle response?
Originally Posted By: A_Harman
That's your prerogative as owner of the car. But you wouldn't be buying the car at all if it wasn't available because it couldn't meet CAFE standards. And don't get me wrong; I think the CAFE law is an abomination to its roots.
A bit flawed in logic. The reason my 2013 Silverado is sold is not because it meets the CAFE standard, it is because GM put out a batch of Chevy Volts and other small vehicles that exceed the CAFE standard thus balancing out the average.
And this AFM thing being some form of gas saver. One has to wonder why my '98 Chevy 2500 with a 454 V8 got almost as good of mpg as my 2013 1500 Silverado with a 5.3L and AFM? And there has been ample stories of folks who have disabled the AFM that experienced no appreciable mpg change. It might show up on the OEM test track, but not really so much in the real world.
That's your prerogative as owner of the car. But you wouldn't be buying the car at all if it wasn't available because it couldn't meet CAFE standards. And don't get me wrong; I think the CAFE law is an abomination to its roots.
A bit flawed in logic. The reason my 2013 Silverado is sold is not because it meets the CAFE standard, it is because GM put out a batch of Chevy Volts and other small vehicles that exceed the CAFE standard thus balancing out the average.
And this AFM thing being some form of gas saver. One has to wonder why my '98 Chevy 2500 with a 454 V8 got almost as good of mpg as my 2013 1500 Silverado with a 5.3L and AFM? And there has been ample stories of folks who have disabled the AFM that experienced no appreciable mpg change. It might show up on the OEM test track, but not really so much in the real world.
Originally Posted By: TiredTrucker
It might show up on the OEM test track, but not really so much in the real world.
You answered your own question. The nature of the beast is that they have to live with the testing procedures set out for them. They can try to be as close as possible to "real world" results, but that's not easy. This becomes more complex since "real world" usage of 1 ton is a lot different than "real world" use of a Ford Focus.
It might show up on the OEM test track, but not really so much in the real world.
You answered your own question. The nature of the beast is that they have to live with the testing procedures set out for them. They can try to be as close as possible to "real world" results, but that's not easy. This becomes more complex since "real world" usage of 1 ton is a lot different than "real world" use of a Ford Focus.
Originally Posted By: A_Harman
Originally Posted By: Shark
Originally Posted By: A_Harman
How lean is your lean cruise? Do you have wideband O2 sensors on it?
16.3:1 at 40mph and above, below about 1/2 throttle. There was a wide band in while tuning. In Australia GM builds this into the tune.
Sounds reasonable. I've been thinking about putting in a tune via HP Tuner to get lean cruise on the highway. I was going to tune it to 15.8, but it seems like a little more is possible. Have you noticed any misfiring or weak throttle response?
No changes in throttle response, [censored] Honda used to put a lean cruise in some Civics that was 22.5:1 afr. Since the V-has a live read for mpg I could literally toggle it on and off while cruising and saw a 3-4mpg change. 16.3 seemed to be what the car liked but it has a cam/headers/fast 92/ported 90mm TB.
Originally Posted By: Shark
Originally Posted By: A_Harman
How lean is your lean cruise? Do you have wideband O2 sensors on it?
16.3:1 at 40mph and above, below about 1/2 throttle. There was a wide band in while tuning. In Australia GM builds this into the tune.
Sounds reasonable. I've been thinking about putting in a tune via HP Tuner to get lean cruise on the highway. I was going to tune it to 15.8, but it seems like a little more is possible. Have you noticed any misfiring or weak throttle response?
No changes in throttle response, [censored] Honda used to put a lean cruise in some Civics that was 22.5:1 afr. Since the V-has a live read for mpg I could literally toggle it on and off while cruising and saw a 3-4mpg change. 16.3 seemed to be what the car liked but it has a cam/headers/fast 92/ported 90mm TB.
Originally Posted By: jrustles
There's just something dumb about continuing to pay inertial and friction costs by dragging the rotating/reciprocating assy around as dead weight to save fuel lol. It just seems like such a backwards way to increase efficiency. Sure, one could work three (or four) cylinders closer to their lowest BSFC, and hope that offsets pumping, inertial and friction losses, but it doesn't strike me as a smart thing to do. It also wears half the engine out more than the other half. At 200K miles, what will we have, one bank with more ring wear than the other? larger bearing clearances on one bank vs the other? more piston pin bore wear?
Yep, build large gas gulping engine with excessive power and add some crazy modifications to decrease the unneeded power and slightly increase fuel efficiency. How crazy is that!
How about building a small fuel efficient engine in the first place and turbocharge it for more peak power when (rarely) needed.
It's called common sense (rare commodity).
There's just something dumb about continuing to pay inertial and friction costs by dragging the rotating/reciprocating assy around as dead weight to save fuel lol. It just seems like such a backwards way to increase efficiency. Sure, one could work three (or four) cylinders closer to their lowest BSFC, and hope that offsets pumping, inertial and friction losses, but it doesn't strike me as a smart thing to do. It also wears half the engine out more than the other half. At 200K miles, what will we have, one bank with more ring wear than the other? larger bearing clearances on one bank vs the other? more piston pin bore wear?
Yep, build large gas gulping engine with excessive power and add some crazy modifications to decrease the unneeded power and slightly increase fuel efficiency. How crazy is that!
How about building a small fuel efficient engine in the first place and turbocharge it for more peak power when (rarely) needed.
It's called common sense (rare commodity).
what anti virus are you using? it seemed ok on my p.c.
Originally Posted By: Garak
Originally Posted By: TiredTrucker
It might show up on the OEM test track, but not really so much in the real world.
This becomes more complex since "real world" usage of 1 ton is a lot different than "real world" use of a Ford Focus.
Then it also becomes a question of why they even had the AFM as part of the pickup engine lineup given that pickups, generally, are used differently than a Ford Focus? This stuff was not mandated by anyone at the government. Maybe getting better efficiency was, but the AFM thing was not. They could have done some better things and thrown in turbocharging or supercharging and got better results than shutting down cylinders.
Originally Posted By: TiredTrucker
It might show up on the OEM test track, but not really so much in the real world.
This becomes more complex since "real world" usage of 1 ton is a lot different than "real world" use of a Ford Focus.
Then it also becomes a question of why they even had the AFM as part of the pickup engine lineup given that pickups, generally, are used differently than a Ford Focus? This stuff was not mandated by anyone at the government. Maybe getting better efficiency was, but the AFM thing was not. They could have done some better things and thrown in turbocharging or supercharging and got better results than shutting down cylinders.
Does this issue include the v6's 07' 3.9 in a impala??
MolaKule
Staff member
Quote:
Maybe getting better efficiency was, but the AFM thing was not.
Better efficiency IS mandated by another one of your efficient and low cost government agency's called the EPA.
It was one of the technologies implemented by GM to obtain fleet CAFE targets mandated by another one of your efficient and low cost government agency's.
Maybe getting better efficiency was, but the AFM thing was not.
Better efficiency IS mandated by another one of your efficient and low cost government agency's called the EPA.
It was one of the technologies implemented by GM to obtain fleet CAFE targets mandated by another one of your efficient and low cost government agency's.
Last edited:
Did you not comprehend my post? I did state that mandates for better efficiency were dictated by congress (true, a inefficient government entity but not the EPA, as CAFE standards are set by legislation and not departmental rule making), but that the AFM thing was not required to do so. That was purely a poor idea from GM instead of taking advantage of much better technology. And it barely made a dent in meeting CAFE standards. Again, I think you must have missed my contention that the main thing that got them to meet the CAFE standards was producing a lot of little go cart cars that no one wanted. Remember, the CAFE standard is the AVERAGE of the entire OEM product line.
The Pickup line has barely budged a bit over the last 20 years regarding fuel economy. Like I stated before, the 2013 5.3L in my Siverado does not get but about 1 mpg better than the 1998 454 big block in my 2500 Chevy. Pretty sad that in 15 years, they could only tweak out 1 mpg better out of an engine that is more "advanced" and is a full 2L smaller, in a 1/2 ton pickup compared to a 3/4 ton pickup. In the final analysis, they have made no progress. The height of insanity is doing the same thing and expecting a different result.
But they are starting to come around. To wit, the 3.2 V6 EBDI engine. As much HP and torque as the 6.6L Duramax diesel and better fuel economy than the diesel, and does it on E85. Has been undergoing testing in Silverado pickups by GM. So, it begs the question why they decided to take antiquated NA engine design and complicate it with no real appreciable results. Kinda reminds me of Scotty on Star Trek in one of the movie versions... "the more complicated they make the plumbing, the easier it is to stop up the drain." They wanted to add complexity, then add something like supercharging or turbocharging to get the results they needed. Ford did it with their Ecoboost V6. As much power as the 5.3L V8 GM engine, reaches the peak torque at a almost 2000 RPM lower than the 5.3L (which is really what you want with a pickup application), and easily gets better fuel economy than the 5.3L.
Oh well, the AFM is disabled on my 5.3L, and in doing so, I am not in violation of any government regulation. Again, that proves it was purely a GM thing and did not have anything to do with the EPA or anyone else. Just like their daytime running lights. Not mandated, and also disabled on my pickup. I realize my mistake in buying a GM pickup, so will not make that mistake next time.
The Pickup line has barely budged a bit over the last 20 years regarding fuel economy. Like I stated before, the 2013 5.3L in my Siverado does not get but about 1 mpg better than the 1998 454 big block in my 2500 Chevy. Pretty sad that in 15 years, they could only tweak out 1 mpg better out of an engine that is more "advanced" and is a full 2L smaller, in a 1/2 ton pickup compared to a 3/4 ton pickup. In the final analysis, they have made no progress. The height of insanity is doing the same thing and expecting a different result.
But they are starting to come around. To wit, the 3.2 V6 EBDI engine. As much HP and torque as the 6.6L Duramax diesel and better fuel economy than the diesel, and does it on E85. Has been undergoing testing in Silverado pickups by GM. So, it begs the question why they decided to take antiquated NA engine design and complicate it with no real appreciable results. Kinda reminds me of Scotty on Star Trek in one of the movie versions... "the more complicated they make the plumbing, the easier it is to stop up the drain." They wanted to add complexity, then add something like supercharging or turbocharging to get the results they needed. Ford did it with their Ecoboost V6. As much power as the 5.3L V8 GM engine, reaches the peak torque at a almost 2000 RPM lower than the 5.3L (which is really what you want with a pickup application), and easily gets better fuel economy than the 5.3L.
Oh well, the AFM is disabled on my 5.3L, and in doing so, I am not in violation of any government regulation. Again, that proves it was purely a GM thing and did not have anything to do with the EPA or anyone else. Just like their daytime running lights. Not mandated, and also disabled on my pickup. I realize my mistake in buying a GM pickup, so will not make that mistake next time.
Sure, that must be why Honda, GM, Chrysler, Bentley, and many more use cylinder deactivation.
They must all be stupid...
They must all be stupid...
Originally Posted By: SteveSRT8
Sure, that must be why Honda, GM, Chrysler, Bentley, and many more use cylinder deactivation.
They must all be stupid...
Here we go again.....
Sure, that must be why Honda, GM, Chrysler, Bentley, and many more use cylinder deactivation.
They must all be stupid...
Here we go again.....
Originally Posted By: daman
Does this issue include the v6's 07' 3.9 in a impala??
Yes, AFM is on the 3.9L but is NOT on the 3.5L.
Does this issue include the v6's 07' 3.9 in a impala??
Yes, AFM is on the 3.9L but is NOT on the 3.5L.
- Status
Similar threads
