Highway Hi-Fi

Highway Hi-Fi was a system of proprietary players and seven-inch phonograph records with standard LP center holes designed for use in automobiles. Designed and developed by Peter Goldmark, who also developed the LP microgroove, the discs utilized 135 grams of vinyl each, enough to press a standard 10-inch LP (12-inch LPs of the period commonly used 160 grams of vinyl each and 45s used roughly 70 grams).

History
The system appeared in Chrysler automobiles from 1955 to 1959 (1956–1959 model years). Records for the system were manufactured exclusively by Columbia Special Products, and could hold roughly 45 minutes of music or an hour of speech per side. This was accomplished by the use of a lower rotation speed of $16 2/3$ rpm (versus $33 1/3$ rpm for conventional long-playing records, and 45 rpm for singles) in conjunction with an extremely tight groove pitch of 550 grooves per inch (216.5 grooves per centimeter), over four times that of a standard monaural LP of the period, and an extremely small ultra-microgroove width of only 0.25 mil, roughly one-third the groove width of a standard stereo LP, at 0.7 mils.

In the most extreme cases of spoken word where high fidelity near the center was not an issue, the recording surface extended to an unusually small diameter of 2+1/4 inch, which constrained the label to 1+1/2 inch for long-playing titles. Demonstration discs and musical selections where high fidelity near the center was an issue were manufactured with standard 3 inch labels.

Manufacture
The players themselves were manufactured by CBS Electronics. According to the official Chrysler press release of September 12, 1955, "Highway Hi-Fi plays through the speaker of the car radio and uses the radio's amplifier system. The turntable for playing records, built for Chrysler by CBS-Columbia, is located in a shock-proof case mounted just below the center of the instrument panel. A tone arm, including sapphire stylus and ceramic pick up, plus storage space for six long-play records make up the unit." A button controlled whether you listened to the radio or the records. A proprietary 0.25-mil (i.e., 0.00025 in or a quarter of a "thou") stylus was used with an unusually low stylus pressure of 2 gf to allow for long stylus life.

Highway Hi-Fi units were factory-installed and were not available as aftermarket add-ons. With a tendency to break or malfunction, and a limited number of titles (which were available solely from one label's back catalog), the product was not a commercial success; Chrysler slowly began to pull support for Highway Hi-Fi as early as 1957 when high warranty service costs became evident. Another automobile record player was manufactured by RCA from 1960 to 1961. This later version dropped the "Highway Hi-Fi" label (not being Chrysler-exclusive) and played standard 45-rpm 7 in records. It, too, suffered a short lifespan: the players were even more prone to malfunction than those manufactured by CBS, and standard 7-inch records had their grooves worn down rapidly by the high stylus pressure used to prevent skipping.