Automotive Wire Frequently Asked Questions
Automotive Wire
What types of insulation are on automotive wire?
There are four distinct types of insultation on automotive wire and cable:
- GPT
- GXL
- SXL
- TXL
GPT is the only automotive primary wire insulation out of the four that is extruded insulation. Extruded insulation is rated -40 C to 80 C. It is created by heating PVC and then extruding it through a die on the stranding. This insulation can be melted with a heat source, changing the form.
The other three automotive wire types, GXL, SXL, and TXL are all crossed-linked insulation. Cross-linked insulation is rated -51 C to 125 C. It is created by extruding PVC through a tube, under heat and pressure, in order to 'cross-link' or change the molecules of the insulation to another state.
How do you determine the Gauge (AWG) of the automotive wire?
Make a small cut about 1/2" long and remove the insulation on the automotive wire. Then you will need to count the individual strands of copper. Next use a micrometer and measure one of the strands. Also count the total number of strands that are present in the automotive wire. Look at the following information to determine the gauge of your automotive wire.
- 7/.028 = 20 (7 strands that measure .028 each equals 20 gauge)
- 16/.030=18
- 19/.029=16
- 19/.027=14
- 19/.025=12
- 19/.023=10
- 19/.021=8
- 37/.021=6
What are some common types of automotive wire and cable and what kinds of applications are they used for?
Trailer cable, SRML wire (high temperature motor lead wire), automotive brake cable, automotive primary wire, battery cable, and speaker cable are all considered automotive wire and cable. Trailer cable can be used on trailers and trucks as well as in other applications where resistance to weather, oil, and grease is necessary. SRML wire is flexible and fire resistant and can be used as motor lead wire or as lead wire for high temperature electrical equipment applications. Automotive brake cable is used for electric brakes in cars, trucks, and trailers. Common applications for primary wire include general circuit wiring and wiring in engine compartments while battery cable is intended for use in starters and battery ground circuits. Speaker cable is designed for use in radios, music systems, public address systems, and other low voltage applications.
What are some specifications and standards I should consider when choosing automotive cable?
Common standards for the automotive industry include those created by the Society of Automotive Engineers (SAE), the American Society for Testing and Materials (ASTM), Underwriters Laboratories (UL), and the Recreational Vehicle Industry Association (RVIA). All of these organizations develop standards for the automotive industry to encourage the manufacture and use of safe and high quality automotive wire and cable. More important specifications to consider are those set by individual car manufacturers. For instance, all of Allied’s primary wire meets both Ford and Chrysler specifications.
Please browse our selection of
Automotive Wire - Primary,
Brake Cable,
Trailer Cable, and
Speaker Wire.