What Is Automotive Wire?

Automotive wire is a flexible wire with stranded conductors for use on low-voltage automotive systems. Conductor material may be copper or aluminum, although automotive wires sold by Allied Wire & Cable (AWC) are copper because of their better durability and current capacity. The most common insulation materials are polyvinylchloride (PVC) and cross-linked polyethylene (XLPE). AWC automotive wire has Society of Automotive Engineers (SAE J-1128) approval, as well as Ford and Chrysler approvals.

Automotive Wire Design

Most car wires use a single conductor, apart from certain specialized applications like electronic brake cables, speaker wires and trailer wiring.


Automotive wires have stranded copper conductors made up of a relatively high number of fine wire strands to ensure flexibility and resistance to fatigue.


The most common automotive insulation materials are PVC and XLPE. Both are tough and abrasion-resistant. PVC is excellent for general automotive wiring. XLPE insulation, with a maximum usable temperature of 125 degrees Celsius, has improved heat resistance and is best for high under-bonnet temperatures.


Multi-conductor cables have a PVC jacket for added protection.


To provide additional protection for this wiring after installation, these wires or cables may often be protected by being installed in a loom or harness of some sort.

What are Common Types of Automotive Wire?

The three common types of wire for automotive are primary wire, multi-conductor jacket wire, and battery cable.

Primary Wire

The term car primary wire applies to single conductor wires for general automotive wiring. PVC insulated wires include GPT wires for internal vehicle wiring, thin-walled TWP wires, and heavy wall HDT wires for underbody applications. XLPE insulated wires include thin-walled GXL for use in under-bonnet and truck wiring harnesses, standard wall SXL wires, and thick wall TXL wires.

Jacketed Wire

You may use multi-conductor wires with a PVC jacket for exposed wiring that's subject to abrasion and road dust. Common applications are for electronic emergency brake cables and trailer wires.

Battery Cable

A battery cable is a heavy-duty cable used for starter wiring circuits, battery grounds, and alternators.

Wire Colors

AWC primary wires come in 10 different colors. For those applications requiring further identification, AWC can add up to three colored spiral stripes to existing cables. Other options include dying, inkjet printing, and laser marking. Contact our Value-Added Services team for further information.

General Specifications for Automotive Wiring

  • Conductors: Stranded pure copper
  • Insulation: PVC or XLPE
  • Jacket: PVC jacket on multi-conductor versions
  • Temperature rating
    • PVC insulation: 85°C to -40°C (some types have a maximum temperature of 105°C)
    • XLPE insulation: 125°C to -51°C

Automotive Wire Approvals

  • SAE J-1128
  • Ford
  • Chrysler

How Is Automotive Wire Different from House Wire?

Automotive wire is different from house wire. Automotive wire is flexible with multiple fine wire strands, while house wiring uses a solid conductor or, if stranded wire, has a small number of relatively heavy-gauge wire strands. House wire doesn't bend as easily as automotive wire and breaks if continuously flexed. It has thicker insulation to withstand the rated voltage of 300 or 600 volts. Automotive wire handles greater temperature extremes than household wire and is approved for vehicle use, while house wire isn't. You should never use standard house wire in automotive applications.