{"id":233154,"date":"2026-06-22T03:38:05","date_gmt":"2026-06-22T03:38:05","guid":{"rendered":"https:\/\/teknomers.com\/en\/there-was-a-time-when-a-thermometer-in-the-car-was-a-luxury-how-this-ingenious-invention-solved-it-in-the-rearview-mirror\/"},"modified":"2026-06-22T03:38:07","modified_gmt":"2026-06-22T03:38:07","slug":"there-was-a-time-when-a-thermometer-in-the-car-was-a-luxury-how-this-ingenious-invention-solved-it-in-the-rearview-mirror","status":"publish","type":"post","link":"https:\/\/teknomers.com\/en\/there-was-a-time-when-a-thermometer-in-the-car-was-a-luxury-how-this-ingenious-invention-solved-it-in-the-rearview-mirror\/","title":{"rendered":"There Was a Time When a Thermometer in the Car Was a Luxury: How This Ingenious Invention Solved It in the Rearview Mirror"},"content":{"rendered":"\n
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Today we have basic elements in our cars that have remained almost in the same place for decades. For example: the thermometer. For many years, we have been able to know what temperature it is outside from the comfort of our car (although sometimes we wonder if the sensor works as it should).<\/p>\n

However, long before this element was incorporated into the instrument panel or the central screen of our car, some manufacturers opted for another place: under the driver’s side mirror. And at a time when analogue predominated, there was no other choice.<\/p>\n

The Luxury America of the Seventies<\/h2>\n

The analog thermometer in the exterior mirror<\/strong> was an innovation hailing from the United States, emerging in the context of the lavish American luxury cars of the seventies. During this era, the most prestigious brands competed fiercely to provide extravagant features, ranging from Cartier watches integrated into the dashboard to systems that opened garages or indicated fuel efficiency.<\/p>\n

The mechanism behind these thermometers was simple yet ingenious. According to enthusiasts sharing insights on forums like Curbside Classic, they functioned using a spiral spring made from materials sensitive to temperature changes (often two metals with differing thermal expansion coefficients, such as brass or iron-nickel alloys).<\/p>\n

Mechanics Behind the Magic<\/h2>\n

One end of the spiral spring fixed to the inside of the mirror housing connected to a small outer drum. As the temperature fluctuated, the spring expanded or contracted, rotating the drum to display the current temperature on a graduated scale. The best part? There were no cables or electronics<\/strong> involved\u2014just pure mechanical precision.<\/p>\n

Moreover, some manufacturers enhanced this feature by incorporating lighting into the fixture, often through a light bulb or fiber optic, sourced from the dashboard (as seen in certain Cadillac models). This method was particularly advantageous, as it did not generate heat and thus did not interfere with the thermometer’s readings.<\/p>\n

Cadillac First, Lincoln Later<\/h2>\n

The brand that first offered this unique feature was Cadillac, the crown jewel of General Motors. According to sources like The Autopian, Cadillacs incorporated these thermometers into their side mirrors around 1976, ahead of their direct rival Lincoln. The Cadillac Seville, a flagship model at the time, prominently featured this accessory, along with the Eldorado, the DeVille, and the Fleetwood.<\/p>\n

As reported by Hagerty Media, this thermometer became an efficient option priced at just $18 within the 1976 Cadillac Fleetwood Brougham’s catalog, making it one of the most economical extras among luxury features like cruise control ($104) or radio cassette players ($239).<\/p>\n

A Luxury That Is Difficult to Find Today<\/h2>\n

Today, finding these mirrors in good condition is considerably rare. For example, a thermometer-equipped mirror for a 1988 Lincoln Town Car may range from $140 to $660 on second-hand platforms like eBay, depending on its condition, while one intended for a 1976-1979 Cadillac Seville can exceed $800.<\/p>\n

By the eighties, Lincoln\u2019s thermometers had evolved to include dual scales for Fahrenheit and Celsius, a feature not present in their late-seventies counterparts. However, Cadillac began to phase out analog thermometers<\/strong> as advanced temperature systems with digital displays gained traction in the early 80s.<\/p>\n

The Leap to Digital<\/h2>\n

The rise of electronic systems rendered these analog thermometers obsolete. In the first half of the 1980s, manufacturers began integrating digital screens into dashboards, showing not only the outside temperature but also a broader range of data. The appeal of digital technology became irresistible to luxury buyers.<\/p>\n

The first car to showcase digital instrumentation was the Aston Martin Lagonda<\/strong>, introduced as a prototype in 1976. Despite being prohibitively expensive for the average consumer, the introduction of liquid crystal LCD screens, particularly the cost-effective TN LCD technology, eventually democratized digital displays in automobiles during the early ’80s.<\/p>\n

As time progressed, displaying outside temperature became a common feature, first in luxury vehicles and soon permeating into the mid-range car segment by the mid-1990s. Today, you will often find the temperature sensor located on the front bumper, strategically placed away from engine heat.<\/p>\n

Seen in perspective, the thermometer in the side mirror was a fascinating product of its time, and even in images, it evokes a sense of mechanical elegance that is hard to replicate today.<\/p>\n

Cover image | The Autopian<\/a> (eBay)<\/p>\n<\/div>\n


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General News – 2<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Today we have basic elements in our cars that have remained almost in the same place for decades. For example: the thermometer. For many years, we have been able to know what temperature it is outside from the comfort of our car (although sometimes we wonder if the sensor works as it should). However, long […]<\/p>\n","protected":false},"author":1,"featured_media":233155,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[36399],"tags":[475,54187,20138,2131,19209,33028,3077,44667,269],"class_list":["post-233154","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-technology","tag-car","tag-ingenious","tag-invention","tag-luxury","tag-mirror","tag-rearview","tag-solved","tag-thermometer","tag-time"],"_links":{"self":[{"href":"https:\/\/teknomers.com\/en\/wp-json\/wp\/v2\/posts\/233154","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/teknomers.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/teknomers.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/teknomers.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/teknomers.com\/en\/wp-json\/wp\/v2\/comments?post=233154"}],"version-history":[{"count":1,"href":"https:\/\/teknomers.com\/en\/wp-json\/wp\/v2\/posts\/233154\/revisions"}],"predecessor-version":[{"id":233156,"href":"https:\/\/teknomers.com\/en\/wp-json\/wp\/v2\/posts\/233154\/revisions\/233156"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/teknomers.com\/en\/wp-json\/wp\/v2\/media\/233155"}],"wp:attachment":[{"href":"https:\/\/teknomers.com\/en\/wp-json\/wp\/v2\/media?parent=233154"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/teknomers.com\/en\/wp-json\/wp\/v2\/categories?post=233154"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/teknomers.com\/en\/wp-json\/wp\/v2\/tags?post=233154"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}