Mach 4 or ''variant'', may refer to: *

Mach number Mach number (M or Ma) (; ) is a dimensionless quantity in fluid dynamics representing the ratio of flow velocity past a boundary to the local speed of sound. It is named after the Moravian physicist and philosopher Ernst Mach. : \mathrm = \frac ...

for four times the speed of sound **

Supersonic speed Supersonic speed is the speed of an object that exceeds the speed of sound ( Mach 1). For objects traveling in dry air of a temperature of 20 °C (68 °F) at sea level, this speed is approximately . Speeds greater than five times ...

of 4 times the speed of sound * ''MACH-4'' (Marvel Comics), a comic book superhero * Fly Castelluccio ''Mach 4'', a paramotor aircraft * Kawasaki ''H2 Mach IV'', the "Mach IV" motorcycle *

.17 Mach IV The .17 Mach IV is a wildcat centerfire rifle cartridge, based on the .221 Remington Fireball case, necked down to fire a bullet. The cartridge was introduced in 1962 by Vern O’Brien. The cartridge offered an easy case conversion and good bal ...

, the .17-calibre ''Mach IV'' center-fire rifle bullet * ''Mach IV'', a personality rating on the rating scale ''

Dark Triad Dirty Dozen The Dark Triad Dirty Dozen (DTDD) is a brief 12-question Personality test, personality inventory test to assesses the possible presence of three co-morbid socially maladaptive, Dark triad, dark triad traits: Machiavellianism (psychology), Machiavel ...

See also