Why do passing trucks suck instead of blow?
Nope, it's not the first line of a joke or a rhetorical question. I would expect a passing truck or bus to be pushing a wave of high pressure air in front and beside, but I've noticed time and agai...
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There is actually an area of lower pressure immediately BEHIND the truck, due to the shape of the airflow over the truck trailer. That's what people who are drafting get in. It sucks a relatively lightweight trailer towards it. Right behind that is an area of turbulence.
