"Large sidewall" tires (high aspect ratio) were prevalent on most automobiles until they were largely discontinued as a mainstream factory option in the 1970s and 1980s due to changing consumer preferences and advancements in tire technology. The automotive industry shifted towards lower-profile radial tires, which offered better handling, safety, and performance.

Description and History: Tires with large sidewalls are characterized by their high aspect ratio, which is the height of the sidewall as a percentage of the tire's width. In the mid-20th century, a high aspect ratio was standard (around 80% to 90%) and contributed to a softer, more comfortable ride.

Key features and historical context:

Aesthetics: The large sidewall provided ample space for decorative elements, most notably the wide whitewall, which was a popular sign of luxury and style from the 1930s through the 1960s.

Construction: Early large sidewall tires were typically bias-ply tires, where the internal fabric plies were laid at an angle to the tire's centerline.

Performance: While comfortable, bias-ply tires had performance limitations compared to modern radials, particularly in handling, traction, and longevity.

Reasons for Discontinuation: The decline of large sidewall tires in mainstream automotive production was driven by several factors:

Technological Shift: The transition from bias-ply to steel-belted radial tire technology offered superior handling, durability, and fuel efficiency.

Performance Demands: Consumers and manufacturers increasingly prioritized performance, safety, and steering response, which were enhanced by shorter, stiffer sidewalls.

Changing Fashion: Automotive styling evolved to favor larger wheel diameters and lower-profile tires, a trend that continues today.

Manufacturing Efficiency: Blackwall tires with modern carbon black compounds were more durable and cheaper/faster to mass-produce than the labor-intensive whitewall tires.