Fuel Efficient Technologies

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Fuel Efficient Technologies
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Technology 1 The Start/Stop Engine

• You may have heard that starting an engine
  requires more fuel than letting a car idle. It
  turns out this isnt true. Enter the Start/Stop
  Engine. First introduced in the 1980s this idea
  has gained traction in recent years.
• Heres how it works. When car comes to a stop
  the engine computer cuts the spark and shuts down
  the engine.
• Then, when the driver lifts his foot off of the
  break or engages the clutch, the car
  automatically restarts.
• (Car and Driver, April 2011)

ILLUSTRATION BY CHRIS PHILPOT. Car and Driver
2009
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Technology 2

• Variable valve timing In older cars the valve
  timing was done on a fixed basis. This meant
  that the car could operate most efficiently only
  at one fixed speed. Variable timing fixes this
  problem by allowing the components of the valve
  train system to work at different rates. At
  lower speeds the smaller parts of the system
  control the firing of the piston, causing the
  valve to open less and thus saving fuel. At
  higher speeds the larger part of the system is
  activated and allows for the greater fuel flow
  necessary for the increased speed. A video
  explaining this in more detail can be seen at
  http//www.youtube.com/watch?vH-ZhbnJ3ZTI

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Technology 3 Continuously Variable Transmission

• Traditional transmissions rely on gears. This
  can be inefficient when a car is at an in-between
  speed (say on a hill) and the engine cant decide
  which gear is best (therefore switching back and
  forth between gears.
• Continuously variable transmissions dont rely on
  gears. Instead they use a pulley system situated
  along a central mechanism which allows the car to
  adjust to the exact speed at which it is
  traveling. This increases fuel efficiency be
  eliminating gear changes.

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Newer versions of the Ford Escape have an active
shutter grill.

• Technology 4 Active Shutter Grill
• In older cars the front grill has vents that
  allow air to flow into the engine. This air is
  used to help keep the engine cool. However,
  manufacturers realized that more air is entering
  the engine than is necessary to keep the engine
  cool. As the air flowing in increased drag
  (decreasing fuel efficiency), the car makers
  figured out that they could design grills that
  close some of their vents at higher speeds, thus
  reducing drag and increasing fuel efficiency.
• (Greencarreports.com, October 8th 2012).

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Technology 5 Direct Fuel Injection
How direct fuel injection works Gasoline engines
work by sucking a mixture of gasoline and air
into a cylinder, compressing it with a piston,
and igniting it with a spark the resulting
explosion drives the piston downwards, producing
power. Traditional (indirect) fuel injection
systems pre-mix the gasoline and air in a chamber
just outside the cylinder called the intake
manifold. In a direct-injection system, the air
and gasoline are not pre-mixed air comes in via
the intake manifold, while the gasoline is
injected directly into the cylinder.
Advantages of direct fuel injection Combined with
ultra-precise computer management, direct
injection allows more accurate control over fuel
metering (the amount of fuel injected) and
injection timing (exactly when the fuel is
introduced into the cylinder). The location of
the injector also allows for a more optimal spray
pattern that breaks the gasoline up into smaller
droplets. The result is more complete combustion
-- in other words, more of the gasoline is
burned, which translates to more power and less
pollution from each drop of gasoline. (Aaron
Gold, about.com guide) http//cars.about.com/od/th
ingsyouneedtoknow/a/directinjection.htm
The 2013 Chevy Malibu Eco uses direct injection,
delivering fuel at high pressure directly into
the combustion chambers. (General Motors photo)
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Technology 6 Multistage Oil Pump
A regular oil pump has chambers for suction and a
discharge chamber. But this one from automotive
supplier Aisin, just introduced in some Toyota
products, has two discharge chambers--one
slightly smaller than normal, and another even
smaller--so you can tailor pressure to when you
actually need it, and divide the discharge in
half. There's full pressure from both chambers at
idle, some from both at medium speed with higher
loads, and full pressure from just the main
chamber with light load conditions. At high rpm,
when a pump would provide more pressure than
needed, the oil flow comes from both chambers but
is reduced by bleeding pressure through the
relief valve. So it essentially reduces the total
amount of work the pump has to, well, pump out.
(Popular Mechanics, October 1, 2009)
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Works Cited 1.) Engine Start Stop Systems on
Non-Hybrid Vehicles Car and Driver, April 2011,
K.C. Colwell/Author, Chris Philpot/illustrator htt
p//www.caranddriver.com/features/engine-stop-star
t-systems-explained-tech-dept 2.) Active
Shutter Grille Vents How they Improve MPG Green
Car Reports, October 2012, Nikki
Gordon-Bloomfield http//www.greencarreports.com/n
ews/1079678_active-shutter-grille-vents-how-they-h
elp-improve-mpg 3.) Direct Fuel Injection, What
it is How it Works About.com, Aaron
Gold http//cars.about.com/od/thingsyouneedtoknow/
a/directinjection.htm 4.) Six Fuel Saving
Technologies to Help Hit 35 MPG Soon Popular
Mechanics, October 2009, Paul Weissler http//www.
popularmechanics.com/cars/news/4261289?clickmain_
sr