When people generically refer to smaller airplanes as "Cessnas" or generically believe that when someone mentions a Cessna, they're talking about a smaller plane. Cessna actually makes bigger, faster aircraft than what people generally know about. Consider the C700 (Cessna Citation Longitude). It can fly at Mach 0.82 at 45,000 feet. A small Cessna, like the ubiquitous 172, can't even get to the 18,000 foot transition altitude, let alone the 27,000 foot altitude where Mach is typically considered for speed, and the airspeed indicator doesn't even suggest it's able to get anywhere near a Mach speed.