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Times are tough for automobile manufacturers. Not only are they vulnerable to financial crisis, they also have to face the ever tightening emission and fuel efficiency requirements. While several technologies were developed rapidly to jack up the power produced by an engine, little was done to improve fuel efficiency until gas prices started skyrocketing. So until Electric vehicles and other forms of energy take over, the mighty internal combustion engine will rule. Everything is being done to extract the maximum from every drop of fuel.

Downsizing, forced induction, hybrids, brake energy regeneration, electric power steering, lighter vehicles are all regular these days. Aerodynamics is one of those fields and overcoming air resistance is one primary objective. So every minute detail is being meticulously designed these days and purposeless holes are closed to avoid unnecessary drag. Chevrolet have gone one step ahead and shut off the lower radiator grille on the Cruze Eco when not needed. By doing so, the boffins at Chevrolet have been able to stretch the range of the Cruze Eco by 0.5 mpg to 40mpg. May not be much but these days, even 0.5mpg is an achievement. So how does the system work? Hit the jump for the explanation, video and press release.

An expert in aerodynamics would tell you that drag in the first obstruction to a moving object (neglecting friction here). So, the smoother the object, more efficiently it plunges through air. Closing any small hole/air pocket will reduce drag by a considerable extent. By closing the lower air intake on the Cruze Eco, Chevrolet engineers have managed to reduce drag by 0.016 and increase fuel efficiency by 0.5 miles per gallon. The reduction in the coefficient of drag (Cd) is considerable when you consider that the Cd of the Cruze 0.31

The system uses a shutter type grille, much like air conditioner vents that can shut completely. In the Cruze Eco, motors operate the shutters. The motor is in turn controlled by sensors. Crucially, the shutter plays an important role in cooling the Cruze’s engine. So when the engine temperature is low (when engine is not up to its normal operating range) or when the vehicle is travelling at a fairly high speed, the shutters close reducing drag. However, when the sensors detect higher engine temperatures, they open to allow air to cool the engine. At lower speeds, the amount of air entering the engine bay is less so the shutter is open up to a specific speed. This is also called active aerodynamics as the shape of the vehicle changes in real time.





info from Auto Tech Blog
 

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...the top grill opening appears to be totally blocked off by the green thingee; while and the bottom opening has the computer-controlled "shutter" mechanism. Since the shutter is controlled by the engine ECU, transplanting this mechanism into a non-Eco vehicle might NOT be 100% successful, unless someother (driver controlled?) way of controlling it is devised.

...also, with a slightly higher-resolution picture, we MIGHT be able to look at the backside of the fog-lamp fascia's to see how they're actually captured/attached.
 

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the green thingy goes in between the upper and lower grille. it is just a piece of foam that give the bumper support.

as far as the fog lights go. mine are held in with one screw, pop in on one side and then two little things that pop in and you have to squeeze the soup out of them to get them to release.
 

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...without parts, it might be awhile before anybody tries that swapping.

...the Eco has only recently been released and produced.
 

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And we like it like that ! So keep up the good work .
 

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Can increase the fuel economy of my 2LT by 3 to 4 mpg by setting the cruise to 65 instead of 72 mph. So how come I don't do this?


If I really want to save on fuel, drive in 5th gear and set the cruise to 30 mph, can average close to 57 mpg.

In terms of weight savings, could save 70 pounds by only filling my tank a quarter full. Ha, saved an extra hundred pound by marrying a woman that weighed 120 instead of 220 pounds, maybe I shouldn't get into this. But feel far more secured with a spare tire than without one.

Another way is to shift at the lowest possible speeds, and to coast long distances. With the former, can't do that when entering a freeway, a good way to get killed. With the latter with a guy behind me, will be parked up my exhaust pipe. When the DOT came to our town, loaded us up with traffic lights that turn red without even another vehicle in sight, can't do anything about this either.

And I won't trade high pressure narrow tires for traction, that extra traction could and has saved my life.
 

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My wife just bought her Eco a few weeks ago. I noticed the shutters are always closed when parked even when warm & the cooling fan kicks on.Is this normal?
From the service manual:

Active Grille Air Shutter Description and Operation
The active grille air shutter actuator closes louvers at the front bumper to enhance vehicle aerodynamics in driving situations where cooling and A/C loads are relatively low and high levels of front end airflow are not required. If high levels of airflow are required the active grille air shutter actuator opens the louvers. The control signal from the fuel pump control module, ignition and ground circuits enable the active grille air shutter actuator to operate. If the conditions for opening the louvers are reached the fuel pump control module commands the active grille air shutter actuator to open the louvers.

The single active grille air shutter system consists of an individual motor operated mechanism hinged behind the vehicle front grille for controlling the amount of air entering the engine compartment. It includes three wires, ground, power and pulse width modulated signal to the actuator. The fuel pump control module determines shutter state based on various vehicle conditions such as vehicle speed, coolant temperature, fan state, refrigerant system pressure, A/C compressor state and ambient temperature. The pulsed signal controlling the shutter mechanism will be able to control the shutter to close/open positions.

The actuator is powered by an ignition circuit that is active when the key is in the RUN position. The vehicle may have to be driven for up to 13 minutes at speeds greater than 41 kph (25 mph) before the shutter begins to move. If low ambient temperature is detected, the shutter will remain in the closed position.
 

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From the service manual:

Active Grille Air Shutter Description and Operation
The active grille air shutter actuator closes louvers at the front bumper to enhance vehicle aerodynamics in driving situations where cooling and A/C loads are relatively low and high levels of front end airflow are not required. If high levels of airflow are required the active grille air shutter actuator opens the louvers. The control signal from the fuel pump control module, ignition and ground circuits enable the active grille air shutter actuator to operate. If the conditions for opening the louvers are reached the fuel pump control module commands the active grille air shutter actuator to open the louvers.

The single active grille air shutter system consists of an individual motor operated mechanism hinged behind the vehicle front grille for controlling the amount of air entering the engine compartment. It includes three wires, ground, power and pulse width modulated signal to the actuator. The fuel pump control module determines shutter state based on various vehicle conditions such as vehicle speed, coolant temperature, fan state, refrigerant system pressure, A/C compressor state and ambient temperature. The pulsed signal controlling the shutter mechanism will be able to control the shutter to close/open positions.

The actuator is powered by an ignition circuit that is active when the key is in the RUN position. The vehicle may have to be driven for up to 13 minutes at speeds greater than 41 kph (25 mph) before the shutter begins to move. If low ambient temperature is detected, the shutter will remain in the closed position.
So if I parked in 37*F weather and the ambient temps warned up, would they open when you open the doors? Reason I asked is I parked with then closed then opened the car to get something and came back hours later to open shutters.


Sent from AutoGuide.com App
 

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thanks. I wonder why they have most of the front grill covered. I guess the engine still gets enough of air. I wonder if these freeze in the winter. I wound think they would...
Aerodynamics/drag. The lower and upper grille still get plenty of air flow; most of the auxiliary cooling (trans cooler, intercooler) are down low in the bumper.

Yes, the flaps sometimes freeze up and piss off the computer. I'm happy to live without them; they've been taken out by snow or small animal strikes on my cousin's Focus 3x.
 
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