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Bought my first new car yesterday :)

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rgun doesn't think that if he runs downhill he would find it easier than when he is running up the hill he just came down.
You can't argue with that kind of dumb
 
Originally posted by: RGUN
Originally posted by: BUTCH1
They just shut off fuel to the "dead" cylinders, the cylinders then use the compressed air to "boomerang" off on another...
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Please elaborate
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From the Wiki link posted by helpme...
How it's done

In order to deactivate a cylinder, the exhaust valve is prevented from opening after the power stroke and the exhaust gas charge is retained in the cylinder and compressed during the exhaust stroke. Following the exhaust stroke, the intake valve is prevented from opening. The exhaust gas in the cylinder is expanded and compressed over and over again and acts like a gas spring. As multiple cylinders are shut off at a time (cylinders 1, 4, 6 and 7 for a V8), the power required for compression of the exhaust gas in one cylinder is countered by the decompression of retained exhaust gas in another. When more power is called for, the exhaust valve is reactivated and the old exhaust gas expelled during the exhaust stroke. The intake valve is likewise reactivated and normal engine operation is resumed. The net effect of cylinder deactivation is an improvement in fuel economy and likewise a reduction in exhaust emissions. General Motors was the first to modify existing, production engines to enable cylinder deactivation, with the introduction of the Cadillac L62 "V8-6-4" in 1981.
 
Originally posted by: desy
rgun doesn't think that if he runs downhill he would find it easier than when he is running up the hill he just came down.
You can't argue with that kind of dumb
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Given the same angle and conditions, its the same total energy that goes into the work. Continue to insult me though.

 
Originally posted by: MovingTarget
Originally posted by: Gobadgrs
Originally posted by: MovingTarget
Congrats! My fiancee has a 2007 LTZ and that is an impressive vehicle. The ride is excellent. As far as the turn by turn navigation is concerned, it is more convenient than a traditional nav system as it allows you to keep your eyes on the road and not on the nav screen. A computer voice comes out of the speakers telling you what to do, and the routes/instructions are updated dynamically based on where you are. As far as fuel economy, the 6cyl deactivates half its cylinders when cruising, so it performs really well in that regard. The 4.0v6 has a lot of power to it you need it though.

GM got it right with this one.
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4.0 v6? Its a 3.6 v6. Whered you hear about cylinder deactivation? Haven't heard about that at all....
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Yeah, the LTZ has that. It even says so on its display below the speedometer which "mode" it is in - 3cyl or 6cyl, in addition to the instant fuel economy in each mode. The impala typically comes in the 3.6, but the LTZ is a 4.0 engine. It isn't uncommon to get 99+mpg instant economy while in 3cyl mode.
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No dude, seriously, GM doesn't make a 4.0L engine.
 
You must overcome the result of vector forces
One way GRAVITY is working for you and the other against you. . .
My gawd
 
Originally posted by: desy
You must overcome the result of vector forces
One way GRAVITY is working for you and the other against you. . .
My gawd
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Gravity is a form of energy.... the total is still the same.
 
All RGUN is missing is a fundamental understanding of physics. He's stuck on the fact that the internal friction of the engine never changed, true, however we're talking about maybe 25hp to drive everything, including the AC compressor, alternator, and entire rotating mass of the engine.

The HP required to maintain a certain speed is that friction, plus or minus whatever the grade is (yes it does take less work to go down than up), plus (and here's the biggy) the air resistance. The air resistance is a function of the drag of the car times the SQUARE of the speed. The math I'm not going to explain, if you want to know, look it up, get a fluids textbook, or an engineering degree. It takes around 60-120hp to maintain 55 mpg. The 'extra' HP is only really needed when you are accelerating the car, so you can save gas by only using the HP you need to keep the car rolling.
 
A huge portion of engine inefficiency is pumping losses. Decreasing displacement (or a host of other things, like running in atkinson cycle per the honda r18), allows you to open the throttle up much further. Pumping losses are greatly reduced.
 
I love the look of the interior. How is the build quality of the interior? Does it feel "plasticky"
 
Originally posted by: RGUN
I guess we're going to just forget that fact that bigger engines are going to tend to be heavier and will require heavier components as well as developing much more friction.

I am not making an unusual claim... it takes a specific amount of power to maintain a specific speed... that is a no brainer... Please refute it with a half decent reason that it saves fuel aside from "it must because if it didnt the all mighty vehicle corporations wouldnt sell it to us"
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Two words: pumping losses.

Deactivating some of the cylinders requires a larger throttle opening to maintain the same power output at a given RPM. This reduces the pumping losses associated with running an otto-cycle engine at part-throttle and increases the overall efficiency.

ZV
 
Originally posted by: lurk3r
All RGUN is missing is a fundamental understanding of physics. He's stuck on the fact that the internal friction of the engine never changed, true, however we're talking about maybe 25hp to drive everything, including the AC compressor, alternator, and entire rotating mass of the engine.

The HP required to maintain a certain speed is that friction, plus or minus whatever the grade is (yes it does take less work to go down than up), plus (and here's the biggy) the air resistance. The air resistance is a function of the drag of the car times the SQUARE of the speed. The math I'm not going to explain, if you want to know, look it up, get a fluids textbook, or an engineering degree. It takes around 60-120hp to maintain 55 mpg. The 'extra' HP is only really needed when you are accelerating the car, so you can save gas by only using the HP you need to keep the car rolling.
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Thank you but my level of understanding of physics is quite high. You always only use the HP required to keep the car rolling... otherwise you would be accelerating, but thats for coming out.
 
Originally posted by: alpineranger
A huge portion of engine inefficiency is pumping losses. Decreasing displacement (or a host of other things, like running in atkinson cycle per the honda r18), allows you to open the throttle up much further. Pumping losses are greatly reduced.
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Cylinder deactivation does not decrease displacement.
 
Originally posted by: Zenmervolt
Originally posted by: RGUN
I guess we're going to just forget that fact that bigger engines are going to tend to be heavier and will require heavier components as well as developing much more friction.

I am not making an unusual claim... it takes a specific amount of power to maintain a specific speed... that is a no brainer... Please refute it with a half decent reason that it saves fuel aside from "it must because if it didnt the all mighty vehicle corporations wouldnt sell it to us"
Click to expand...

Two words: pumping losses.

Deactivating some of the cylinders requires a larger throttle opening to maintain the same power output at a given RPM. This reduces the pumping losses associated with running an otto-cycle engine at part-throttle and increases the overall efficiency.

ZV
Click to expand...


There we go finally a reasonable answer, so working the remaining cylinders harder brings them into a higher operating efficiency and therefore fuel savings?
 
Sweet ride. I don't loathe the chocolate or "cocoa" or whatever they call it colored inserts as much as I thought I would. Saw some promo pics of an Aura with them way back when and wasn't a big fan. Looks a bit better in pics than I anticipated. Good luck with the car.!
 
Originally posted by: RGUN
Originally posted by: desy
You must overcome the result of vector forces
One way GRAVITY is working for you and the other against you. . .
My gawd
Click to expand...


Gravity is a form of energy.... the total is still the same.
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You are one dense mofo.

Waiting for the: "You are quick to say I am wrong, but where is the proof!?"

The proof: You think a car going up a hill uses the same amount of energy from the ENGINE than if it were going down a hill.

Somebody ban this flamethrower.
 
Originally posted by: shocksyde
Originally posted by: RGUN
Originally posted by: desy
You must overcome the result of vector forces
One way GRAVITY is working for you and the other against you. . .
My gawd
Click to expand...


Gravity is a form of energy.... the total is still the same.
Click to expand...

You are one dense mofo.

Waiting for the: "You are quick to say I am wrong, but where is the proof!?"

The proof: You think a car going up a hill uses the same amount of energy from the ENGINE than if it were going down a hill.

Somebody ban this flamethrower.
Click to expand...

Can we please keep this thread about Gobadgrs' Malibu?
 
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