Fender skirts
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Fenders skirts are pieces of bodywork that cover the upper portions of the rear tires of an automobile. They are typically detachable to allow for tire changes.
They are implemented for both aerodynamic and aesthetic reasons.
Fender skirts were seen on many American cars between the 1940s and 1960s, going out of favor after that. They were often paired with whitewall tires. The extent of the skirt also varied, before the 50s it was common for all but the bottom inches of the rear tire to be covered, while by the 60s fender skirts only covered a few inches of the top of the tire and were largely absent afterwards. Fender skirts remained for some time longer on a few cars, particularly large American luxury cars.
For example, up until 1996, the Chevrolet Caprice, Oldsmobile 98, Buick Skylark, Oldsmobile Achieva, Buick Roadmaster, Cadillac Deville, and Cadillac Fleetwood all wore fender skirts to some degree. However, most of these models were eliminated after 1997. The Deville name survived, but was redesigned and the fender skirts were removed. As of 2005 only the Honda Insight comes with the once common fender skirts, although they are available for some new cars as aftermarket accessories.
Some cities, such as Los Angeles, have fender skirts on municipal buses, as they can prevent items in the road from slipping under the tires.
The fender skirt is also simply referred to as a DIUI, pronounced die-yi.