While truck body designers had introduced strategic curves before the mid-‘60s, Rudkin-Wiley Corp. took aerodynamics a bit further when it brought out the first bolt-on aero device for trucks in 1965. The Air-Shield retro-fit mounted on the cab roof, guiding air over the top of the trailer, thus greatly reducing drag at highway speeds.
Ads claimed fuel savings of $200 to $1,600 per year (not bad in an era when fuel cost well under $1) and a drag reduction as high as 21 percent on cabovers. This reduced shifting and transmission wear and, in some applications, allowed use of a smaller engine for further fuel savings.
The device ultimately drove a revolution in cab aerodynamics in which Rudkin-Wiley played a part by providing tractor and trailer fairings. Rudkin-Wiley was renamed Airshield and is still in business as Star Composites, though it no longer makes truck aero devices.