no
The Mustang GT (2011 model) has a 6-speed manual transmission standard and a 6-speed automatic transmission optional. The 2010 Mustang GT had a 5-speed manual transmission standard and a 5-speed automatic transmission optional.
The 1987 Ford Mustang came with a T-5 five-speed manual or optional automatic transmission.
The 2007 Ford Mustang has a 5-speed manual.
The 2003 Ford Mustang has a 5-speed manual.
The 2009 Ford Mustang has a 5-speed manual.
The 2014 Ford Mustang has a 6-speed manual.
The 2006 Ford Mustang has a 5-speed manual.
The 2010 Ford Mustang has a 5-speed manual.
The 2005 Ford Mustang has a 5-speed manual.
The 2004 Ford Mustang has a 5-speed manual.
The 2002 Ford Mustang has a 5-speed manual.
The 2013 Ford Mustang has a 6-speed manual.