It's a flat, flat world, at least for two wire harness
producers who said they expect copper consumption to remain
level, or even decline, going forward despite the red metal
being the material of choice for the increased wiring needed to
support a growing array of "gadgetry" in new vehicles.
"Copper is the traditional metal for wiring. It is the metal
of choice due to its properties. It is easy to use and very
conductive," said Randy Sumner, innovation manager at
Streetsboro, Ohio-based Delphi Electrical/Electronic
Distribution Systems. However, given the price and weight of
copper, plus the fact that you can fit only so much wiring into
the wire harness without needing more space, "the need for
wiring optimization is paramount," and that could affect the
amount of copper used per electrical harness. "We are looking
to minimize copper use to fit into the constraints that we
have," Summer said.
Nevertheless, he acknowledges that demand for copper wiring
per vehicle has been rising.
Eric Leszczynski, senior technical specialist with Yazaki
North America Inc., Canton, Mich., agreed. "As automakers
increase the gadgetry or 'wow' factor of their vehicles, it
requires additional electrical circuits." And more electrical
circuits per vehicle means more wire per vehicle, he said.
"About 99 percent of all automotive wire is copper, as it
has been since the beginning of the automotive industry. Every
now and then aluminum is mentioned as a substitute and it has
been used in one car here and one car there, but copper remains
While the long-term curve for the number of electrical
circuits used per vehicle is clearly on the rise, it's very
difficult to quantify, given that the number rises and falls at
any given point in time, Leszczynski said. "Engineers are
continually combining certain systems to lessen the cost
associated with more copper wiring, which results in the
elimination of some circuits. But then as new gadgets are
introduced, the number of circuits goes up again. It's a give
Currently, the average upper-end light vehicle has about
1,200 circuits, of which a good amount-probably 60 to 65
percent-is to power the drive system, he said. Much of the
rest-about 30 percent-is used to process information for
"infotainment," which includes navigational systems, DVD
players and other electrical and electronic gadgets.
The pressure is clearly on the upside. This not only
includes the circuits for gadgets installed into the vehicles
themselves but those for all portable electronics-cell phones,
laptop computers, portable navigation devices, MP3 players,
satellite radios and televisions-that are brought into vehicles
as plug-in devices, Sumner said.
"That drives the need for extra power outlet ports and
receptacles in cars to charge or run these devices during the
ride." Leszczynski said. "We never had 110-volt circuits in
cars before, but now we are seeing household-type three-prong
plugs as well as USB ports."
Some Ford Motor Co. vehicles, for example, are being
equipped with SYNC, an in-car connectivity system that
according to the Dearborn, Mich.-based automaker allows users
to operate most popular MP3 players, Bluetooth-enabled cell
phones and USB drives with simple voice commands.
Hybrid and electric vehicles, which are growing in
popularity, also require a significant increase in wiring,
Sumner said. "Wiring is needed to electrify the propulsion
unit, which means that big wires with very high amperage and
voltage are needed. That results in a lot of wire harness
Besides all the added features, there are packaging
challenges even in conventional, internal combustion engine
vehicles. To deal with those pressures, as well as efforts to
reduce weight and costs, Sumner said wire harness makers
analyze all of the electrical circuits to keep the amount of
copper to the lowest achievable level without compromising
vehicle safety and functionality.
One thing that wire harness producers are doing is
developing ever-smaller wire gauges. "About 12 years ago the
thinnest gauge wire was 20 gauge," Leszczynski said. But now
22-gauge wire is commonly used, and preliminary steps have
already been made to go down as far as 26 gauge. Going from 22
gauge to 26 gauge represents a 66-percent decrease in copper
consumption as the wire is copper alloy rather than pure copper
due to strength considerations, he noted.
Delphi Automotive Systems also has been working on a major
program to develop aluminum circuits as replacements for
copper, Sumner said, although he acknowledged that there are
some disadvantages with aluminum-primarily that it is less
conductive than copper and more prone to galvanic corrosion.
"But it is lighter and less expensive," he said.
While aluminum wire would need to be one gauge size larger,
it still would represent a massive cost savings compared with
copper, he said. And while taking measures to protect aluminum
wire from corrosion would add a little to the cost, it should
still be less expensive than copper.
To date, the substitution of aluminum for copper circuits
has been fairly limited. "We are just now starting to see some
aluminum battery cables in some cars," Sumner said. "We are a
few years away from seeing inroads in other wiring."
Leszczynskiis not so sure. Unless it is proven that the
substitution would reap significant cost savings, he questioned
whether aluminum would make any sizable inroads at all.
Instead, he expects copper consumption for auto wiring in
vehicles other than hybrids and electric cars to remain
relatively flat as the increasing number of circuits offsets a
decline in circuit sizes. MYRA PINKHAM