Shaping air: three hundred hours in the tunnel

A grand tourer earns its range in the wind tunnel long before it earns it on the road. Over eleven weeks we ran the Aurea GT body through 312 hours of tunnel time, and the changes that survived were, almost without exception, invisible.

Eleven millimetres

The largest single gain came from lowering the leading edge of the front splitter by eleven millimetres. It bought us 0.006 in drag coefficient — roughly 19 kilometres of range at motorway speed. Nobody will ever notice it, which is the point.

The wheels were harder. A closed-face wheel is aerodynamically superior and visually inert; an open spoke is the opposite. We settled on a turbine profile with a hidden inner disc, which recovers most of the benefit and still reads as a wheel from three metres away.

What we did not do

We did not fit active aero flaps. They work, they add 14 kilograms, and they are one more thing to fail in year nine. The car we want to still be good in 2046 is the one without them.