Mach number which was also unit-first, and may have influenced the use of the term Mach. In the decade preceding faster-than-sound human flight, aeronautical engineers referred to the speed of sound as "Mach's number", never "Mach 1". Mach number is useful because the fluid behaves in a similar manner at a given Mach number, regardless of other variables. As modeled in the International Standard Atmosphere, dry air at mean sea level, standard temperature of , the speed of sound is . The speed of sound is not a constant; in a gas, it increases as the absolute temperature increases, and since atmospheric
Ford Mustang Mach 1 Lincoln Aviator, and the 2003–2009 Australian Boss 5.4 L V8s (see Ford of Australia Boss 5.4 L), the engine also has intake camshafts sourced from Lincoln's 5.4 Liter "InTech" V8 to provide more mid-range torque. The Mach 1 engine had a 10.1:1 compression ratio in contrast to the 1999 and 2001 Cobra's 9.85:1, and the Mach 1 was equipped with a Windsor Aluminum Plant or WAP block unique from the Teksid aluminium blocks used in the 1996–1999 Cobras. The Mach 1 also featured a relatively high redline of 6,800 rpm (5-speed cars) and fuel cut off at 7,050 rpm "or