A sport utility vehicle (SUV) is a generic marketing description for a rugged automotive vehicle similar to a station wagon but built on a light-truck chassis. Usually equipped with four-wheel drive for on or off road ability, some SUVs include the towing capacity of a pickup truck with the passenger-carrying space of a minivan. SUVs are considered light trucks and often share the same platforms of pickups and thus are regulated less stringently than passenger cars under two major laws in the U.S.—the Energy Policy and Conservation Act for fuel economy standards, and the Clean Air Act for emissions standards

It is known in some countries as an "off-road vehicle" or "four-wheel drive", often abbreviated to "4WD" or "4x4", pronounced "four-by-four". However, not all SUVs have four-wheel drive capabilities. Conversely, not all 4WD passenger vehicles are SUVs. Off-road vehicles are a very different class of vehicles, being vehicles primarily built for off-road use. Although some SUVs have off-road capabilities, this is often a secondary role and they often do not have the ability to switch between 2WD, 4WD high gearing and 4WD low gearing. While automakers frequently tout a particular SUV's off-road prowess with advertising and naming, the daily use of SUVs is largely paved roads and urban areas.

Initially extremely popular in the late 1990s and early 2000s, the SUV's popularity has since declined, due to criticism regarding excessive gasoline consumption, pollution, cost, and poor safety. Due to high oil prices and a declining economy since the mid-2000s, manufacturers have responded to buyers' complaints. The traditional truck-based SUV is gradually being supplanted by a new vehicle type, the crossover SUV, which uses an car platform for lighter weight and better fuel efficiency, but is no longer designed or recommended by the manufacturer for off-road usage or towing.

Design characteristics

Although designs vary, the SUVs have historically been mid-sized passenger vehicles constructed using a body-on-frame chassis similar to that found on light trucks. They usually have gasoline engines, often employing similar engines as pickup trucks, while a few SUVs are diesels.

Most SUVs are designed with a square cross-section, an engine compartment, a combined passenger and cargo compartment, and no dedicated trunk (i.e. a station wagon body). Most mid-size and full-size SUVs have three rows of seats with a cargo area directly behind the last row of seats. Compact SUVs and mini SUVs may have five or fewer seats, especially if they are based on a car platform instead of a light truck.

A few of the most known design characteristics of SUVs are their high ground clearance, upright, boxy body, and high H-point. Lately, SUV bodies have become more aerodynamic to reduce wind resistance and improve fuel economy.