A gasser is a type of hot rod originating on the dragstrips of the United States in the late 1950s and continued until the early 1970s. Gassers are based on production models from the 1930s to mid-1960s, which have been stripped of extraneous weight and jacked up using a beam axle to provide better weight distribution on acceleration (beam axles are also lighter than an independent front suspension), though a raised stock front suspension is common as well. Common weight reduction techniques include fiberglass body panels, stripped interiors and plexiglass windows (sometimes color tinted).
Because they were primarily built for racing, these cars typically had the engine swapped to a larger or more powerful one, or the existing stock engine modified (often heavily). It was very common to fit a Roots supercharger modified from original use on General Motors two-cycle diesel truck engines and mechanical fuel injection, manufactured by Algon, Hilborn, or Crower.
With form being dictated by function, their appearance is often very top heavy and ungainly, largely due to front ends being raised higher than stock, to assist in the weight transfer during rapid acceleration (racing). Having their exhaust pipes exit through the front fender well is a common characteristic of gassers, as is having bodies painted in flamboyant metalflakes, pearls, and candy finishes complemented by lettering in wild fonts.. Most gassers also had ladder bars.