[cellsafemode]

The only real problem people here have with dropping to v4 mode is sound related when they have removed the afm valves. Everything else is psychosomatic. It works fine and only works when you aren't driving sporty and it does improve mileage over time.

I've had numerous trips ( both directions) where I've been over 40mpg both ways and I'm doing about 80mph.

The transmission is probably more responsible for that than the engine... But you will see a few mpg due to afm. Anywhere from 0 to 7 from what I've seen on the v6 over the past 4+ years. The v8 is more drastic so maybe they get more but they have more rotating and static weight

[MrRuss]

Sure on long highway trips you notice better MPGs, mixed daily driving much less so and all city driving hardly at all. I live 6 miles from work all city streets and averaged 18 MPG prior to modding, 17 MPG average now.

[AmazinglySmooth]

My 2018 Suburbans have it and my 2011 Denali had it. I can't feel it when it engages or disengages. In TX, we have lots of highway driving so it doesn't kick on, but above 70 it is more rare. My SS is a manual.

[cmitchell17]

Do the manual cars have the V8 icon? You would think they would have taken out the V8 icon since it doesn't make sense to put it in there if its just going to stay on V8 all the time? You know you have a V8?

[dpevans]

The only reason they have it is government mandated gas mileage regs.

[Petrol Head]

Originally Posted by cmitchell17

Do the manual cars have the V8 icon? You would think they would have taken out the V8 icon since it doesn't make sense to put it in there if its just going to stay on V8 all the time? You know you have a V8?

No there are no indicators on the dashboard. If it’s something that comes up in the DIC, no it’s not in the ECM programming on manuals. If the icon is a back lighted static indicator molded into the plastic of the speedometer or tachometer dials, yes it’s in every SS trim and above that use this instrument cluster. But the lamp isn’t installed/illuminated on manuals.

All 8 cylinders are running 100% of the time (as it should be) in manuals. No need for my car to tell me

[Petrol Head]

Originally Posted by dpevans

The only reason they have it is government mandated gas mileage regs.

Same reason our manuals have CAGS. Both gimmicks help avoid the gas guzzler tax.

Difference is we can eliminate CAGS for $15 and 5 minutes under the car.

Can’t eliminate the variable cylinder management for $15 can ya? Lol

[ember1205]

Originally Posted by Petrol Head

No there are no indicators on the dashboard. If it’s something that comes up in the DIC, no it’s not in the ECM programming on manuals. If the icon is a back lighted static indicator molded into the plastic of the speedometer or tachometer dials, yes it’s in every SS trim and above that use this instrument cluster. But the lamp isn’t installed/illuminated on manuals.

All 8 cylinders are running 100% of the time (as it should be) in manuals. No need for my car to tell me

Mmmm... not really.

There are a number of variables like trim level, specific dash configuration, and which screen you're viewing in addition to there possibly being some differences between model years. On mine (2020 2SS, 6MT), as one example, it always shows "V8" when viewing the trip odometer using the standard instrument configuration.

[cmitchell17]

Originally Posted by ember1205

Mmmm... not really.

There are a number of variables like trim level, specific dash configuration, and which screen you're viewing in addition to there possibly being some differences between model years. On mine (2020 2SS, 6MT), as one example, it always shows "V8" when viewing the trip odometer using the standard instrument configuration.

I think in some certain limp modes when ETC is high, it will use V4 mode to try to keep the cylinder head temp down, I wonder if it would switch over then. I just don't get why they didn't remove the V8 indicator entirely on the manuals, I guess they are just that cheap.

[UnknownJinX]

Originally Posted by Petrol Head

All 8 cylinders are running 100% of the time (as it should be) in manuals. No need for my car to tell me

Personally, as an engineer, I like the idea behind it(reducing pumping losses), but the execution has proven itself to be problematic historically, so I don't really trust the idea.

Originally Posted by cmitchell17

I think in some certain limp modes when ETC is high, it will use V4 mode to try to keep the cylinder head temp down, I wonder if it would switch over then. I just don't get why they didn't remove the V8 indicator entirely on the manuals, I guess they are just that cheap.

My 19 doesn't have that icon AFAIK. Must be a 2020 Model Year thing.

[He11bent]

Originally Posted by JasonGofast

The ZL1 A10 doesn't have it. Do the SS and RS have it?

I don't particularly want it, but I feel I'm about wear out the hinges on the fuel tank door.

A10 SS has it. My 2011 had it as well. I've never had an issue with it. Cant tell it kicking in or out even watching the cluster change.

[ember1205]

Originally Posted by cmitchell17

I think in some certain limp modes when ETC is high, it will use V4 mode to try to keep the cylinder head temp down, I wonder if it would switch over then. I just don't get why they didn't remove the V8 indicator entirely on the manuals, I guess they are just that cheap.

It isn't an "indicator"... It's a graphic in the display. Removing it would COST money because it would amount to reprogramming the computer to not show it. It's much simpler and cheaper to leave it alone and have it never switch over to V4 mode because it's never in that mode.

[MarksCamaro]

Originally Posted by ride_002000

Be thankful you don't have it. It's not good and most deactivate it through a tune or range device

Hi there, I have just bought a 2SS auto in the land Down Under! I noticed on my first highway drive that it would move between V8 and V4 almost without detection and fuel consumption would drop too.

Just wondering what the problem is with it?

[MakCamaro]

I have it and I think it's a great feature. I never notice it when it switches from V8 to V4 and back. I don't see why people want to deactivate it.