Optimizing Aerodynamics of a Truck: Part 5
![Image](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjp_cA2E9qmT8chipZjHwbakZ0Xg1bzU_hJVM5msUUOSQ9ySo8VN2fORwl8BJyroWnBZGg1nFTjWcDLwmaecMq1fYZca3X5GMemSmg_vbM1N2-H91RA9pHCZB5l0Vuy_suoIfptRL4MwOagRgnVTl6bkkB-ZyNfv2FStMS6loyzA6tIlqvCFQmjxEET/w640-h360/20230111_125917.jpg)
After my last round of testing , I made a permanent version of the air dam extensions I tested: This brings my truck’s aerodynamic drag down to around 84-85% of what it was before I started this project: Modification Percent Change mirrors removed, grill blocked -4.0% 9” air dam -8.6% air dam extensions -3.8% Total -16.4% I didn’t expect to get that much with these changes, especially because I haven’t even tested anything on or around the bed, rear undercarriage, tailgate, rear wheel housings, or rear bumper. Tailgate Many websites claim that lowering a truck’s tailgate increases its drag. This was even explored on an episode of the popular television show Mythbusters ; the show’s hosts put a model truck in a water tunnel to illustrate the recirculation that happens in the bed (and ran some fuel economy tests with the tailgate down, removed, and replaced with