February 23, 2026
Crosswinds & Crossfire
A NASA Engineer Discovered a World of Semi Truck Aerodynamics by Accident
NASA bike scare sparks truck aero revolution—and a comment war over US vs EU rigs
TLDR: A NASA bike scare led to rounded truck edges and fairings that slash drag and boost fuel economy, shaping modern rigs. Commenters are brawling over why the industry didn’t do this sooner, with a US-versus-Europe showdown on safety, rules, and whether aero even matters at lower speeds.
A NASA engineer literally got pushed around by a semi’s wind wake on a bike in 1973—and turned the chaos into a fuel‑saving revolution. Edwin J. Saltzman slapped sheets of metal on a van, rounded the edges, and boom: 52% less drag. Seal the underside? Another 7%, for an estimated 15–25% better highway fuel economy. Later tests on an actual semi added curves, fairings, and even a boat‑tail, proving the wind really hates boxy trucks.
But the real action is in the comments. amelius is side‑eyeing the industry: “Do truck makers not hire aero people?” Meanwhile pjc50 reminds everyone this world of tweaks is “constrained and pushed forward by what’s road legal,” pointing to Volvo’s aero updates. Then it gets spicy: masklinn says Europe’s strict length and speed limits make aero less crucial, while bluGill fires back that American rigs are aerodynamically better (and maybe safer). masklinn isn’t having it: “There are European cabovers in the US.” The meme energy? “Fast & Curious: Semi Edition,” plus jokes about NASA inventing the “truck makeover.” In short: science nailed the airflow, but the crowd is split on whether US trucks already win or if Europe’s rules make the real difference.
Key Points
- •In 1973, NASA engineer Edwin J. Saltzman observed semi-truck wakes and initiated aerodynamic testing.
- •NASA modified a Ford van, establishing a boxy baseline and progressively smoothing surfaces and sealing the underside.
- •Rounding all four front edges cut drag by 52%; sealing the underside added a 7% drag reduction, with 15–25% estimated fuel economy gains.
- •Similar modifications on a cab-over-engine semi truck reduced drag by over 50%; underbody fairings and a boat tail later delivered a 15% drag reduction.
- •NASA’s research influenced modern trucks, with widespread use of fairings, rounded corners, and vortex generators like Airtab; efforts parallel DOE’s SuperTruck program.