Trying to decide, so I've got a question about Active Fuel Management

[VenomZ302]

So I'd like an SS, but I'd also like a manual. However, I was wondering about what the boost from AFM would actually be? Does anyone have any experience with what kind of increase you might see? Especially on a sportier car?

Thanks in advance.

[BeermanSS]

No experience, my stepbrother had a Tahoe rental the first year it came out, AFM that is, and the only time we could get it to activate was coasting downhill. HA HA. In a much lighter vehicle and built on a much more powerful engine, I'm sure that would be a lot different. I think they only say like a 3-5% gain though while activated. Not sure, anyone feel free to correct me.

[Inspector 17]

Look at it this way, if you go with the stick you get 20+ more HP. AND gas is down to less than $2 in many areas.

[BeermanSS]

and it will stay that way till holidays, and then, till summer driving season next year when it'll hit $5 a gallon. Dont forget it nearly hit 5 this year.

[BeermanSS]

The two cars will be so close in MPG's its worthless to make that a factor.

[blackZbandit]

There is no increase in fuel efficiency in the auto with AFM, both the AT and the MT are expected to acheive 23-24 MPG hwy and about 17-18 city. You do (supposedly) get an extra 22 horses with the manual, but with the optimized shift points on the auto they're both acheiving 0-60 times of approximately 4.6 seconds... so will you ever feel the extra 22 horses? Probably not. So really the decision just boils down to whether an Auto or Manual trans will work better for you. Me, I live in L.A. which = TRAFFIC so I will be getting an auto. Maybe you've got more open roads and lighter traffic in Charleston so the manual may work out better for you.

[SemperFi]

Originally Posted by BeermanSS

The two cars will be so close in MPG's its worthless to make that a factor.

...gotta hide from that

From further up... counting on gas staying around 2 bucks is extremely shortsighted. OPEC will cut production again, and we will all see gas prices shoot back up.

And this, that they will be so close, is also inaccurate. If all you do is drive from a downtown apartment to the office.. maybe. Because itl only kick on on the highway. But for people like me, that get about half of their miles or more on the highway... that will be significant. Throw on the cruise control and feel the glorious sip of only 4 cylinders. (I say sip only in comparison with the funneling gulp of all 8) But still...

[SemperFi]

Originally Posted by blackZbandit

There is no increase in fuel efficiency in the auto with AFM, both the AT and the MT are expected to acheive 23-24 MPG hwy and about 17-18 city. You do (supposedly) get an extra 22 horses with the manual, but with the optimized shift points on the auto they're both acheiving 0-60 times of approximately 4.6 seconds... so will you ever feel the extra 22 horses? Probably not. So really the decision just boils down to whether an Auto or Manual trans will work better for you. Me, I live in L.A. which = TRAFFIC so I will be getting an auto. Maybe you've got more open roads and lighter traffic in Charleston so the manual may work out better for you.

Before i could even respond to the first load of horse... crap, i get more of it. Lets just think practically for a moment. Do you think GM would spend considerable money developing a new engine and adding technologies if it werent even going to do anything.... Noooo. Then lets consider what this technology they spent money developing does... IT SHUTS DOWN HALF THE ENGINE ON THE HIGHWAY. Tell me please... how would 4 and 8 cylinders burn the same amount of fuel?

[TAG UR IT]

autos always eat more gas than manuals.

prime example. turtle and i both drove our 2002 SS's up to Indy in Sept.

His is an auto and mine is a manual.

I got 26mpg's average and he got 22mpg's average. We both drove together and we had pretty much identical driving habits.

WAIT!!! They are both LS1's!!! sorry....

Again, I might not be able to explain it as well as some of the other gearheads can, but I will say this. The auto eats more gas than a manual. Same thing for the LS3 vs. L99. L99 without AFM would not get the same mpg's....it would be lower.

Both the LS3 and L99 are going to get the same miles per gallon. And, the only REAL test that will prove this is when they are running around on the streets and we are able to perform our own tests.

[SemperFi]

Im sure you know a good bit about cars. but i have to go against you here. New cars (within the last 3 years) have autos that get just as good, or better MPG than manuals.

When im not as tired ill come and give some examples, but i really think all of you bashin the AFM are just upset that it might actually be smarter not to drive a stick camaro. Sorrry...

[GTAHVIT]

^ I don't see that anyone is bashing the AFM. All anyone is saying is that it has to overcome the lower gas mileage found in auto tranny's. For the most part eryone is applauding it's capabilities.

Maybe our standards should be higher, but, any auto that gets the same mpg as a manual in the same car is good right?

[theholycow]

Originally Posted by SemperFi

how would 4 and 8 cylinders burn the same amount of fuel?

It's bound to be close; the same amount of energy is required to move the car, and engine friction doesn't go down much -- it's still only got one crankshaft, and those pistons are still moving. The valves are shut off, so those pistons aren't pumping any air (instead, the air in those cylinders acts as a spring, releasing almost as much energy as is stored in it during each stroke), and the active pistons have to make all the power. The 4 active pistons still have to make as much power as the 8 pistons would make.

This saves fuel because the engine is operating slightly closer to its optimum BSFC range, among other reasons. However, the difference isn't very much, and the real world results seem to be about a 5 to 10% difference at best -- about enough to make up for the common difference between automatic and manual under EPA testing.

A driver who is willing to shift early and shift often can almost certainly get better MPG from the manual than the AFM-equipped auto, though if the paddle shifters are obedient then the auto with AFM might come out ahead.

[VenomZ302]

Thanks for the information. I really just wish they could (or just would?) put a switch somewhere on the console/steering wheel/wherever that determines how many of the cylinders are operating. But oh well. Maybe that would be bad for the engine or something.

Didn't know that it would really only kick in on the highway. That probably means that I'd rarely ever use AFM. Looks like I'll have to research it a bit more, and hey, I won't be getting the Camaro for about a year, so I've got some time to decide.

[theholycow]

I would love a switch, and to have it available with the manual transmission. I bet I'd get 35mpg easily.

In the Camaro it will almost certainly operate much more than it does in a full size truck. The Camaro has a much better power-to-drag ratio, so AFM might kick in for almost any steady cruise.