Dressing up rolling gear keeps a hefty aftermarket busy in the automotive industry, setting trends, raking in "fat stacks" and distinguishing cars and trucks of all types from their siblings. Booming consumer interest has made hubcaps, or wheel covers, widely watched commodities. Today, these terms are used interchangeably. Technically, though, they are not the same.

The hubcap appeared early on the automobile, designed for necessity rather than style. Like so many automotive parts - bumper, roof, seatbelt, rearview mirror - the hubcap's name speaks its function. A wheel's hub is its center, the part that fits around the axle and from which wooden spokes, on early cars, radiated to the rim supporting the tire. Grease at the axle minimized friction, but any contaminants would have destroyed its effectiveness. The cover that helped exclude dirt and grit from this area was called a hubcap. During the 1920s, steel spokes replaced wood ones. By the 1930s, hubcaps became larger and a place for manufacturers to print their names or symbols, like V-8.

The next trend in wheels was for steel "disks" to displace wire wheels. Steel wheels were plain to look at and so wheel covers, obscuring some or all of the wheel rather than covering only the hub, became popular ways to dress up the wheels. Wheel covers may occupy just the inner, bolt area of the wheel, or span all of the wheel's visible surface. The former style have names like "dog dish" and "baby moon," reflecting their look and shape. The contours on a full-wheel cover like the '50 Cadillac led to the name "sombrero."

Custom hubcaps featuring crossed bars or a nude woman also found a ready market among drivers seeking a different look from the pack. Lowrider Magazine has an online article discussing wheel and hubcap trends popular on lowered cars: Lowridermagazine.com.

Wheel covers were typically steel and often chrome plated. Auto manufacturers placed their name or symbol in the center. The true hubcap lay below that mark protecting the grease, while the wheel cover beckoned eyes in plain view. Wheel covers' common symbols and words are as familiar as family - the Ford script, the Chevy bowtie, VW's graphic with the first letter centered in the second, the Cadillac crest, De Soto's "DeS," the Pontiac chief head, Audi's four rings... Sometimes the wheel cover mimicked an earlier, or classier, type of wheel - a spoked cover making the steel wheel below it look like a wire wheel.

Wheel covers have finished the looks of countless iconic automobiles over the decades, but they have a drawback - one that spawned a niche salvage market. When the wheel strikes a sizeable bump or hole, a wheel cover can dislodge and head for the brush. Buildings with their walls lined in hubcaps are a familiar roadside sight, and many of these outfits have sold or still sell hubcaps.

Today, most hubcaps are plastic wheel covers. They are not as popular as in days of old because light alloy wheels have become popular, designed with attractive styles and finishes of their own. Wheel covers have not disappeared, though. They continue in plastic form on base model vehicles, and in

spinning form at substantial cost. There are also non-spinning rims, spinners' opposite, which are engineered and weighted to stay in place and not turn. Low riders had rims of this sort decades ago and a company in the 1990s revisited this idea with stationary hubcaps featuring advertising.

Originally a necessity, the hubcap matured to take its place as a frontrunner feature in automotive style.