With key focus on cost cutting and vehicle weight reduction, the North American automotive industry is beginning to transition from copper to aluminum wiring. The Electric Wiring Component Application Partnership (EWCAP) is managing this conversion process.


Aluminum was approved by Underwriters Laboratories to be used in housing since 1945. But it was to be applied with a lot of caution such as up-sizing the aluminum conductor, use of appropriate switches, outlets and termination systems. Due to negligence of the proper methods to use aluminum wiring, people still relate aluminum to shortcuts and house fires.  Be it a house or automobile, aluminum wiring if used with proper guidance and technology can go a long way.

Why prefer aluminium over copper?

Copper prices are skyrocketing thereby encouraging the use of aluminum wiring. Aluminum has a lower cost per amp and a total of 48 percent mass reduction. Since, aluminum’s specific gravity is lower than copper, adopting aluminum electric wire will guarantee a weight reduction of 20-40 percent as electric wire by itself and about 10-30 percent as wire harness. Aluminum is lighter to handle hence facilitating a quick and easy assembly as opposed to copper wires and handles that are difficult to lift and manage.

Aluminum metal is abundantly found in the earth’s crust making it a favorable alternative to copper. Though copper has a high demand in the construction industry, copper is scarcely found thereby leading to hike in copper prices when compared to aluminum.

European and Japanese markets have already started switching to aluminum in automobiles. Aluminum battery cables have been used in many Daimler vehicles and few other companies have followed the trend too. Japanese automakers have begun to replace wiring harness application with aluminum.

US automakers are keen to adopt the same, but they are thoroughly considering six main challenges that surround the change:

  • Aluminum conducts only about 60 percent when compared to  Hence, aluminum conductors need to be up-sized by two gauges to replace copper wires.
  • Aluminum has a lower tensile strength than copper.
  • Aluminum produces thick oxide layers which are more than copper or any other metal. Thus, termination systems should be able to break these layers to alleviate better metal contact.
  • Aluminum has different coefficients of thermal expansion which can lead to thermal shocks and galvanic corrosion.
  • Aluminum relaxes more over time hence leading to higher resistance.

The US automakers believe that there are various solutions to combat these challenges which with upcoming standards will allow for easy development.