How a NASA Engineer Discovered a World of Semi Truck Aerodynamics by Accident
Hacker News
February 18, 2026
AI-Generated Deep Dive Summary
NASA aerospace engineer Edwin J. Saltzman discovered the potential of aerodynamic improvements for semi-trucks through an accidental yet insightful experience while biking to work in 1973. Observing how passing trucks disrupted airflow and nearly caused him to lose control, Saltzman realized the opportunity to reduce drag and improve fuel efficiency for these massive vehicles. His innovative approach involved transforming a Ford van into a testbed, systematically modifying its shape to minimize air resistance. By rounding corners, sealing underbodies, and adding fairings, his team achieved remarkable results—reducing drag by up to 52% and boosting estimated fuel economy by 15-25%. This breakthrough not only advanced truck aerodynamics but also demonstrated how principles from aerospace engineering could be applied to terrestrial vehicles.
Saltzman’s project began with basic experiments on the van, using aluminum sheets to create a boxy profile that mimicked contemporary trucks. Through incremental changes—such as smoothing front edges and adding underbody fairings—the team measured drag reductions at each stage. Later tests on a semi-truck cab revealed similar benefits: rounding front corners alone cut drag by over 50%, while additional modifications like boat tails further reduced it by 15%. These findings highlighted the importance of aerodynamic design in optimizing heavy vehicle performance.
The impact of Saltzman’s research extended beyond immediate fuel savings. His work inspired modern truck features, including aerodynamic fairings, rounded corners, and vortex generators (like Airtab), which are now standard in the industry. This innovation aligns with initiatives like the Department
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Originally published on Hacker News on 2/18/2026