| 4x4 Terminology
Although in the strictest sense, the term "four wheel drive" refers to a capability that a vehicle may have, it is also used to denote the entire vehicle itself. In Australia, vehicles with offroad capabilities are referred to as "four wheel drives". This term is sometimes also used in North America, somewhat interchangeably for SUVs and pickup trucks and is sometimes erroneously applied to two-wheel-drive variants of these vehicles.
The term 4x4 (read either four by four or full times four) is used to denote the total number of wheels on a vehicle and the number of driven wheels; it is often applied to vehicles equipped with either full-time or part-time four-wheel-drive. The term 4x4 is common in North America and is generally used when marketing a new or used vehicle, and is sometimes applied as badging on a vehicle equipped with four wheel drive. Similarly, a 4x2 would be appropriate for most two-wheel-drive vehicles, although this is rarely used in the USA in practice. In Australia the term is often used to describe Utes that sit very high on their suspension. This is to avoid the confusion that the vehicle might be a 4x4 because it appears to be otherwise suited to off-road applications. A 2×4, however, is unambiguously a piece of lumber.
Large American trucks with dual tires on the rear axles (also called duallys or duallies) and two driven axles are officially badged as 4x4s, despite having six driven wheels because the 'dual' wheels behave as a single wheel for traction purposes and are not individually powered. True 6x6 vehicles with three powered axles such as the famous "Deuce and a Half" truck used by the U.S. Army has three axles (two rear, one front), all of them driven. This vehicle is a true 6x6.
Another related term is 4-wheeler (or four wheeler). This generally refers to all-terrain vehicles with four wheels and does not indicate the number of driven wheels; a "four wheeler" may have two or four wheel drive.  |