The sustainability of our environment and the energy we use
to support society are dominant concerns across the globe.
Rising concentrations of carbon dioxide in the atmosphere and
shrinking availability of petroleum from secure sources have
led to focused efforts on policy and technology solutions.
Against this larger backdrop, the global automotive fleet of
roughly 700 million cars represents a significant source of
CO2. By some estimates, 14 percent of global CO2 emissions are
from transportation-with cars making up the lion's share. As
such, reducing vehicle fuel consumption and related tailpipe
emissions are vital to combating climate change and lessening
our reliance on foreign oil.
The aluminum content in cars and light trucks reached an
all-time high of 8.6 percent of average vehicle curb weight in
2009, continuing almost 40 years of uninterrupted growth in
North America. The main driver behind aluminum's success is the
environmental advantages the high-strength, low-weight,
infinitely recyclable metal provides. As a result, it is no
surprise that in a recent study by Ducker Worldwide LLC, Troy,
Mich., auto industry experts ranked aluminum use as a top
option and "very significant" in meeting the federally mandated
fuel economy improvements of 40 percent by 2020.
It's well accepted that lighter vehicles can minimize both
the fuel consumption and carbon emissions associated with their
use. In fact, a 5- to 7-percent fuel savings can be realized
for every 10-percent weight reduction by substituting aluminum
for heavier steel. In terms of curbing greenhouse gas (GHG)
emissions, each pound of aluminum replacing two pounds of iron
or steel in a car or truck can save a net 20 pounds of CO2
equivalent emissions over the typical lifecycle of a
According to the International Aluminium Institute, London,
the aluminum content of vehicles manufactured in 2006 alone
will lead to potential global savings of approximately 154
million tons of CO2-equivalent GHG emissions and an energy
savings equivalent to about 16 billion gallons of crude oil
over the life of the vehicles. If you extend using aluminum to
reduce the weight of the world's transportation fleet
(including cars, trucks, trains, planes and sea-going vessels),
the potential exists to reduce GHG emissions by 660 million
tons annually, or close to 9 percent of all global,
transportation-related GHG emissions.
When considering how automotive material choices impact
total energy use related to GHG, it's important to note that a
vehicle's true lifecycle covers three discrete phases
production, use and end-of-life.
In terms of total impact on the environment from all three
phases, it would be misleading to simply consider the energy
used during the production phase alone. That is why the U.S.
Automotive Materials Partnership reports that the energy
required to produce aluminum is small relative to the energy
used by a vehicle over its lifetime. Given aluminum's
incredibly high recycling rates, its environmental footprint is
even smaller than one might initially realize.
The aluminum industry is already the world's largest user of
renewable energy, with more than 55 percent of primary aluminum
globally produced from hydropower; that number jumps to more
than 70 percent from hydroelectric sources in North America.
Specific to recycling, more than 55 percent of the aluminum
used on North American vehicles is recycled. Better still,
recycled aluminum takes 95 percent less energy to produce than
primary aluminum. And as further evidence of aluminum's
infinite recyclability and durability, more than 70 percent of
all the aluminum ever produced is still in use today.
Today, automakers are hyperconscious of these environmental
issues and they are breaking new ground with redesigned
vehicles and high-tech powertrains to meet the challenge.
Plug-in hybrids like the Chevy Volt and full electrics like the
Nissan Leaf are poised to revolutionize the auto industry and
the very makeup of the vehicles we all drive. Generally, these
need new fuel-saving powertrains, which come with an added
cost. As the cost of powertrains goes up, the value of
lightweighting vehicles, regardless of their powertrains, also
increases since it requires less energy to move a lighter
vehicle. In fact, for some types of electric vehicles,
replacing heavy steel with aluminum actually reduces the total
cost of the car because fewer batteries are needed to move the
It is well known that diesel and hybrid powertrains provide
better fuel economy over standard internal combustion engines,
but at an increased cost to the consumer. In addition, advanced
powertrains have a payback period of several years compared
with gasoline engines at equivalent vehicle performance. Add in
aluminum and the new, lighter platform on its own typically
costs more-at least upfront-than a current platform. However,
by reducing the weight of the vehicle, the power requirements
can be correspondingly reduced, leading to a more affordable
powertrain and vehicle. The fuel savings gained offsets the
additional cost of the platform and powertrain within one to
four years. As a result, aluminum's value proposition in the
automotive sector is increasing nearly as fast as its
Almost everyone agrees that we must reduce GHG emissions in
automotive applications and reduce our dependence on foreign
oil. Yet both must be done in such a way that it won't bankrupt
automakers or consumers. For this, there is no silver bullet.
The answer, instead, lies in a holistic solution consisting of
safe and smart design, lightweighting and advanced powertrains
that offer real-world solutions to today's challenges of
meeting the promise for a better tomorrow.
Randall Scheps is chairman of the Aluminum
Association's Aluminum Transportation Group and marketing
director of ground transportation for Alcoa Inc.