I've taken several C7 owners for rides in my car and they couldn't believe the difference.
No Range device for C8
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Nov 23, 2021, 02:13 PM
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Z mode or Track. Not sure why anyone would disable it in a C8, it is 100% invisible.
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Good to hear that the C8 has vastly improved on the V8 to V4 switch over.
Melting Slicks
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From: SUFFIELD CONNECTICUT
V4 mode unfortunately cannot be disabled "yet" as far as I know. I also am waiting for a range device or having it tuned out when tuning or adjusting the ecm becomes available.
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Melting Slicks
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From: SUFFIELD CONNECTICUT
If your butt meter and ears are as sensitive as mine , you will feel and hear AFM taking place. As good as the system is, I still would rather not have it take place, especially for a very small difference in MPG. Lets see how many C8 owners shut down the AFM system when it becomes possible.
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If your butt meter and ears are as sensitive as mine , you will feel and hear AFM taking place. As good as the system is, I still would rather not have it take place, especially for a very small difference in MPG. Lets see how many C8 owners shut down the AFM system when it becomes possible.
Last edited by Roger Austin; Nov 24, 2021 at 06:24 PM.
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From Ask Tadge:
Tadge answered:
Can AFM be turned off by putting the car in manual mode? How long before it goes back to auto mode?
Assuming I purchase a Z51 with magnetic ride, can I disable AFM by putting it in PTM?
Assuming I purchase a Z51 with magnetic ride, can I disable AFM by putting it in PTM?
We know some customers are not fans of AFM (Active Fuel Management, otherwise known as cylinder de-activation). They worry it will sound bad, or feel bad as it transitions in and out of V4 mode, or just don't like that the engine doesn't always run on all cylinders. Manufacturers around the world are being put under tremendous pressure to reduce fuel consumption and greenhouse gases. As a result, you see a massive move to electrification, hybridization and small displacement charged engines. General Motors is fully embracing the initiative and has a stated goal to get to a zero emissions future.
So how does Corvette fit into this picture? Even before global greenhouse gas concerns became mainstream, Corvette prided itself on efficient operation. After all, low mass, low drag and efficient engines make for a better sports car. There are a lot of ways to get fuel efficiency and some of them negatively impact the driving experience. Our manual transmission skip-shift we had for years was not a customer favorite, but it helped economy and kept us away from gas-guzzler taxes. The bottom line is that we have to make choices that balance the owner's experience (including operating cost) and our impact on the planet.
Our AFM system is very effective on the small block V8. It lets us close the valves on the de-activated cylinders so the cylinders act as air springs. When the engine rotates we get energy back as the compressed air in the cylinder expands. Other manufacturers just stop fueling the de-activated cylinders and so don't get much fuel savings. The reason 4-cylinder operation is more efficient is that the active cylinders are worked harder with a greater throttle opening. That's like taking a restrictor out of the system saving pumping losses. On Corvette, AFM saves more fuel than start/stop, a feature becoming very prevalent in the marketplace. For many cars, start/stop is a great choice because it is almost transparent to the occupants. Not so on a Corvette. Our engine has a lot of character, so when it stops running it is very noticeable. We have received a lot of very strong input from customers that they would not like it.
One of the innovations on the 2020 Stingray is the integration of AFM with a DCT. We a quite proud of how seamless we've been able to make it. We believe we are getting the efficiency benefit with virtually no compromise to the driving experience. Numerous drive impression articles have been written and I do not remember reading any negative comments about it. Bottom line is that we must balance conflicting demands and make smart choices so we can continue to offer the driving pleasure of a naturally aspirated V8 engine.
So now to the heart of your question. Yes, when you are in manual mode the engine stays in V8. That is true either by hitting the "M" button or by entering "temporary tap" by pulling one of the paddles. Temporary tap will revert to "Drive" after about 5 seconds if you don't request an additional shift in that time. AFM is also de-activated in "Track" mode. Since PTM is only available in Track mode, the answer is yes to that one too. If you are in PTM, it will be V8 only. New for 2020 is the "Z" mode which will come from the factory set up as an extra sporty mode including shift schedules pulled from the "Track" mode, so that will be V8 only. Of course, you can customize "Z" mode any way you want, so if you elect another shift pattern, AFM will return.
So how does Corvette fit into this picture? Even before global greenhouse gas concerns became mainstream, Corvette prided itself on efficient operation. After all, low mass, low drag and efficient engines make for a better sports car. There are a lot of ways to get fuel efficiency and some of them negatively impact the driving experience. Our manual transmission skip-shift we had for years was not a customer favorite, but it helped economy and kept us away from gas-guzzler taxes. The bottom line is that we have to make choices that balance the owner's experience (including operating cost) and our impact on the planet.
Our AFM system is very effective on the small block V8. It lets us close the valves on the de-activated cylinders so the cylinders act as air springs. When the engine rotates we get energy back as the compressed air in the cylinder expands. Other manufacturers just stop fueling the de-activated cylinders and so don't get much fuel savings. The reason 4-cylinder operation is more efficient is that the active cylinders are worked harder with a greater throttle opening. That's like taking a restrictor out of the system saving pumping losses. On Corvette, AFM saves more fuel than start/stop, a feature becoming very prevalent in the marketplace. For many cars, start/stop is a great choice because it is almost transparent to the occupants. Not so on a Corvette. Our engine has a lot of character, so when it stops running it is very noticeable. We have received a lot of very strong input from customers that they would not like it.
One of the innovations on the 2020 Stingray is the integration of AFM with a DCT. We a quite proud of how seamless we've been able to make it. We believe we are getting the efficiency benefit with virtually no compromise to the driving experience. Numerous drive impression articles have been written and I do not remember reading any negative comments about it. Bottom line is that we must balance conflicting demands and make smart choices so we can continue to offer the driving pleasure of a naturally aspirated V8 engine.
So now to the heart of your question. Yes, when you are in manual mode the engine stays in V8. That is true either by hitting the "M" button or by entering "temporary tap" by pulling one of the paddles. Temporary tap will revert to "Drive" after about 5 seconds if you don't request an additional shift in that time. AFM is also de-activated in "Track" mode. Since PTM is only available in Track mode, the answer is yes to that one too. If you are in PTM, it will be V8 only. New for 2020 is the "Z" mode which will come from the factory set up as an extra sporty mode including shift schedules pulled from the "Track" mode, so that will be V8 only. Of course, you can customize "Z" mode any way you want, so if you elect another shift pattern, AFM will return.
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From: cumming ga
Wait till your lifters stick and you have to have engine pulled apart to replaced cam and lifters took 6 weeks car engine block and crank and pistons only thing still in block front suspension pulled off exhaust off. You can keep your V4 mode no thanks
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From: Central Illinois
It's absolutely ridiculous to not want it to work. Those that bitch about it apparently have zero understanding of when it occurs. It ONLY happens when you are at steady state and NO acceleration is occurring. Your G meter is showing 0.0, how on earth would you know (or care) if the car is steady state being pushed by 1,2,4, or 8 cylinders? If you even touch the gas pedal it instantaneously changes back to V8. There is no one on earth that drives the car on public streets that is in a constant state of acceleration, no one. I just love all these super sensitive people because not most, but every single person that has ridden in my car I tell them when it switches to V4 and every one of them say "really, I didn't hear or feel anything". 100% of the time when I squeeze the gas it's a full on V8 C8.
Instructor
Joined: Sep 2021
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It's absolutely ridiculous to not want it to work. Those that bitch about it apparently have zero understanding of when it occurs. It ONLY happens when you are at steady state and NO acceleration is occurring. Your G meter is showing 0.0, how on earth would you know (or care) if the car is steady state being pushed by 1,2,4, or 8 cylinders? If you even touch the gas pedal it instantaneously changes back to V8. There is no one on earth that drives the car on public streets that is in a constant state of acceleration, no one. I just love all these super sensitive people because not most, but every single person that has ridden in my car I tell them when it switches to V4 and every one of them say "really, I didn't hear or feel anything". 100% of the time when I squeeze the gas it's a full on V8 C8.
Melting Slicks
Joined: Nov 2012
Posts: 3,163
Likes: 686
From: SUFFIELD CONNECTICUT
It's absolutely ridiculous to not want it to work. Those that bitch about it apparently have zero understanding of when it occurs. It ONLY happens when you are at steady state and NO acceleration is occurring. Your G meter is showing 0.0, how on earth would you know (or care) if the car is steady state being pushed by 1,2,4, or 8 cylinders? If you even touch the gas pedal it instantaneously changes back to V8. There is no one on earth that drives the car on public streets that is in a constant state of acceleration, no one. I just love all these super sensitive people because not most, but every single person that has ridden in my car I tell them when it switches to V4 and every one of them say "really, I didn't hear or feel anything". 100% of the time when I squeeze the gas it's a full on V8 C8.
Race Director
Joined: Aug 2019
Posts: 12,351
Likes: 14,183
From: Central Illinois
