• Aug 11th 2010 at 4:59PM
  • 37
Click above to watch the video after the jump

While we'd all love to see 1,000-horsepower supercars that effortlessly reach 100 miles per gallon, the pace of fuel economy improvement is far less aggressive. Automakers are scratching and clawing for every mpg they can find by doing things like downsizing and turbocharging engines, adding direct injection and variable valve timing, utilizing electric power steering and cutting weight. Another great way to save fuel is through improved aerodynamics, as evidenced by an enhancement made to the 2011 Chevrolet Cruze Eco that helps the new C-segment sedan reach 40 mpg on the highway.

The Eco Cruze utilizes an innovative automatic air shutter system that closes the grill vents at higher speeds to reduce drag by .016 – adding .5 mpg and helping push the Cruze to the magic 40 mpg number. The shutter system is fitted to sensors that measure changes in speed or temperature. If the temperature drops or the sensors measure sufficiently high speeds, the vents will be closed by electric motors, cutting down the amount of air that enters the engine bay. Why not simply keep the grill vents closed all the time? Because added airflow is needed to help cool the engine at lower speeds. Follow the jump to read the General Motors presser and watch a minute-long video that shows how the shutter system works.

[Source: General Motors]

Show full PR text
DETROIT – Squeezing out every last drop of fuel efficiency is one of the key tasks for Greg Fadler, aerodynamics engineering group manager at Chevrolet.

Fadler and his team worked on making the 2011 Chevrolet Cruze Eco one of the most fuel-efficient small cars on the market, achieving up to an estimated 40 MPG on the highway – hybrid-like efficiency without the hybrid cost.

Engineers used some of the proven approaches to making the Cruze Eco a gas sipper, trimming its overall weight and lowering the ride height. But the real innovation is behind the front grill where an automatic air shutter system allows the car to change shape and cut through the air more smoothly.

The air shutter system uses sensors to feel and sense wind and temperature conditions. The sensors are married to electric motors that open and close the shutters automatically. With the shutters closed at high speeds, wind drag is reduced. At lower speeds, the shutters open to maximize engine-cooling air flow. The air shutter system contributes nearly half a mile per gallon in combined city and highway driving.

The cooling systems for all GM vehicles are designed for the worst-case scenario, which is pulling a trailer up a grade in Death Valley. The shutter allows them to significantly improve fuel economy, while still providing the cooling needed in that extreme case.

"The real fun of the job is when we discover something new or innovative that allows us to do something better than we or our competition has done before," Fadler said.

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    • 1 Second Ago
      Mark Rode
      • 6 Months Ago

      There is a better method on tap now. See adaptive fairing patent on create the future design contest.... http://contest.techbriefs.com/2014/entries/automotive-transportation/4497

      The entire radiator and shutters still back up pressure with active grille shutters. The adaptive fairing make the radiator appear smaller and smaller when not needed. This is what is on tap for the 2nd generation fix.

      • 5 Years Ago
      At this rate my great great grandchildren shall own their very own Autobot!!!! lol
      Pretty neat trick to be honest, curious if in the future we'll be seeing cars that automatically lower themselves at highway speeds to even futher mpg. I know some have in the past but making it standard..
      • 5 Years Ago
      Ummmm.... the video posted seems to be a video about a restored Olds 442. Not the grill on the Eco Cruze.
      • 5 Years Ago
      Yes, the Porsche 928 had this long ago. Many cars employ active aero dynamics. Porsche for instance offers the controversial pop up rear wing that helps improve downforce at high speed. Now many brands offer a similar device. Some cars have variable length intake systems, or camshafts, and lets not forget ignitions and fuel injection. Heck, if we go back to carburetors, there were hood scoops with vents that opened and closed as well.
      • 5 Years Ago
      I'd like one for my Prius please!
      • 5 Years Ago
      So how does this really help? A 200lb person will get less MPG than a 125lb person.

      Or the person that lets their tires drop a few PSI. Or gasoline with more Ethanol.

      .5mpg can be made up or lost by varying driving characteristics between people.

      Adding a piece of pointless tech that can easily break and increases cost is fairly stupid. I'm sure the .5mpg could have been made up by eliminating the extra weight and finding a set of wheels and tires that weigh less.

      All this is good for is eco-maniacs to have something to point out as to why thier car is better than yours.
        • 5 Years Ago
        GM researched and built the car. You pull figures out of your behind.

        Why makes you think GM didn't think of the same things as you and try them before adding other more complex changes?
        • 5 Years Ago
        Yes, there are a number of variables, aren't there?

        But this is a *constant*. It ALWAYS adds 0.5 mpg. So when you're accelerating hard with 13.5 mpg, 0.5 mpg of that comes from this modification. When you're cruising at 65 mph with a tailwind getting 75 mpg, the benefit is still there, though contributing less to the whole.

        Well okay, the picture's more complex than that -- it'll contribute 0.5 mpg on average; probably ranging from 0 to 1 mpg typically, with the greater benefit at higher windspeeds. So, if you're heading into a strong wind at high speed, you could be benefitting by as much as 2 mpg from a 35 mpg total.

        The point is, this is always going to benefit. If the driver lost some weight, you could join in the fun, too.
      • 5 Years Ago
      Wow, automatic cardboard. What WILL they think of next?
      • 5 Years Ago
      This is one of several 'new' technologies that should've been implemented in Nascar years ago....EcoBoost Ford entry anyone?
        • 5 Years Ago
        Why? There's no benefit to a race series which operates under one condition per race. If the temperatures are lower for a particular race, I'm sure they break out the duct tape and seal off some of the cooling intake.

        This has been a long time coming precisely because it's a technology *not* applicable to racing.
      • 5 Years Ago
      Adding the 80s corolla to the list of cars that already use this feature
      • 5 Years Ago
      I give the little motors and their connectors three winters up north at most before they fail from salt corrosion. How about either the Ford airfoil system (Ford? God forbid!) or a counterweight that closes the shutters when airflow slows? Of course, everything these guys make is assembled dry so it freezes up ASAP.
        • 5 Years Ago
        Perhaps. A thermostatic spring will work, and isn't affected by corrosion. If you've ever seen a fan casing or anything else metal underhood in the salt belt, you'll know how fast they're attacked. We get degraded surfaces in six weeks or less. Those who've never seen this can't imagine the damage.
      • 5 Years Ago
      Will these shutters still open and close when packed with bugs? How easy will they be to keep clean?
      • 5 Years Ago
      Nice Olds.
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