Grey

Grey or gray (see spelling differences) is an intermediate color between black and white. It is a neutral or achromatic color, meaning literally that it is a color "without color". It is the color of a cloud-covered sky, of ash and of lead.

The first recorded use of grey as a color name in the English language was in AD 700.Grey is the dominant spelling in European and Commonwealth English, although gray remained in common usage in the UK until the second half of the 20th century.Gray has been the preferred American spelling since approximately 1825, although grey is an accepted variant.

In Europe and the United States, surveys show that grey is the color most commonly associated with neutrality, conformity, boredom, uncertainty, old age, indifference, and modesty. Only one percent of respondents chose it as their favorite color.

Etymology

Grey comes from the Middle English grai or grei, from the Anglo-Saxon graeg, and is related to the German grau. The first recorded use of grey as a color name in the English language was in AD 700.

Four-wheel drive

Four-wheel drive, 4×4 ("four by four"), 4WD, and AWD is a form of drivetrain capable of providing power to all wheel ends of a two-axled vehicle simultaneously. It may be full-time, or on-demand, and may be linked via a transfer case to provide multiple gear ranges.

A four-wheeled vehicle with power supplied to both axles may be described as "all-wheel drive". However, not all "four-wheel drive" vehicles are "all-wheel drive", as vehicles with more than two axles may also be described as "four-wheel drive" regardless of how many axles, so long as two axles (of two wheel ends apiece) are powered.

Definitions

4WD/AWD systems were developed in many different markets and used in many different vehicle platforms. There is no universally accepted set of terminology to describe the various architectures and functions. The terms used by various manufactures often reflect marketing rather than engineering considerations or significant technical differences between systems.

4×4

Four-by-four (4×4) refers to the general class of vehicles. The first figure represents the total wheels (more precisely, axle ends, which may have multiple wheels), and the second, the number that are powered. Syntactically, 4×2 means a four-wheel vehicle that transmits engine power to only two axle-ends: the front two in front-wheel drive or the rear two in rear-wheel drive. Alternatively, a 6x4 vehicle has three axles, any two of which provide power to two wheel ends each. The number of wheels may be greater than six, as on ubiquitous ten-wheel tractor units, but the designation stays the same.