Hier, dans Mythbusters, il était justement question de çà...
Les deux savants fous ont testé le mythe à bord d'une 997 cabriolet, et il a été démontré qu'à 145 km/h, plus aucune goutte ne pénétrait dans l'habitacle (capote ouverte, bien entendu).
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Et voici leurs conclusions :
Driving a convertible with the top down in the rain at a high speed will ensure that no water can enter the driver compartment.
plausible
The MythBusters first performed several small scale tests, using a model car and a wind tunnel, and found that at higher speeds, a sort of air bubble seemed to form around the driver compartment, giving credence to the myth. In their full scale test, they used an actual convertible as well as a 200 foot rain bar to provide the rain. In a control test, they stopped the convertible in the middle of the rain to put up the top, and the interior was soaked. Then they drove through the rain at 70 mph (113km/hr), and saw that the interior was significantly less wet than the control. Next, they then drove the car through the rain at 90 mph (145km/hr) and saw that the interior was not wet at all. The MythBusters attributed this to the car’s windshield, which served its function as well as creating an air bubble over the interior of the car. However, they decided to declare the myth “plausible, but not recommended” due to the inherent danger of driving at such high speeds on wet roads.
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