The XC90 is a distant outlier on the graph.
Every dot is scattered closely around a line that shows a steady downward trend in a paper titled Influence of Aerodynamics. Every dot but one.
Covering 1955 to 2010, the graph shows Volvos consistently becoming more aerodynamically efficient – and the XC90, which arrived in 2002 and was way above the norm.
The list of examples shows why. From PV544 and Amazon through 240, 245, 760, 960, 850, S80 and V70, they’re all saloon or estate cars. The drag coefficient (Cd), a measure of slipperiness through air, gradually improved.
In the late 1950s, the PV544, a handsome two-door saloon, had a Cd of 0.50. The Amazon bettered that, with 0.48Cd. By the 1980s, figures in the low 0.40 range was normal,…
