Gary Zhou 
The Tesla Semi is not like other Class 8 trucks in the market. It’s all-electric, it can travel 500 miles on a single charge, and it’s zero-emissions. It also is equipped with a large mono wiper, which, as per a recent sighting, actually seems to work very well in the rain.
The video of a new Tesla Semi sighting was recently posted in the r/TeslaMotors subreddit. The short clip seemed to be recorded from a Tesla’s built-in dashcam, and it showed a Tesla Semi wrapped in Frito-Lay decals traveling in the rain. Due to the rainy weather, the Semi’s windshield wiper was engaged.
The short video showed the Semi’s mono wiper system, which uses two moving sub-arms that actively steer a single wiper, working in real-world conditions. Despite the Semi’s large windshield, one could see that the mono wiper system was cleaning a wide portion of the glass with each swipe. Some Tesla enthusiasts in the subreddit, however, have noted that such a wiper system may run into some problems during icy conditions.
Mono wipers have never really become mainstream save for a few consumer vehicles, and definitely not for Class 8 trucks like the Tesla Semi. Mercedes-Benz infamously rolled out its “eccentric sweep” mono blade wipers in the 1980s, which cleared 86% of the windshield in a vehicle like the W124, more than any production car at the time, as per Hemmings. The novel mono wiper system was quietly retired in the 90s, however. Speculations suggest that this was partly due to the system being more complex and slower than a conventional dual wiper system, among other reasons.
Tesla appears to be fond of mono wipers for its larger vehicles. The Semi was launched with a single wiper setup, and as one could see in the recently-shared video, it actually seems like a great idea. The Cybertruck, however, was unveiled without a wiper at all, but sightings of production beta units in the wild suggest that the all-electric pickup truck might also be equipped with a single wiper system.
There is an issue, however. Unlike the Semi’s mono wiper, which is set up in the middle of the windshield, the Cybertruck’s large, single wiper in its production beta units is situated only on the driver’s side. This suggests that the all-electric pickup truck’s wiper system would likely not be as good as the Semi in rainy weather. Tesla seems to be aware of this problem though, with Elon Musk admitting on Twitter that the Cybertruck’s wiper system is something that “troubles” him the most about the vehicle.
Watch the Tesla Semi’s mono wiper system in action in the video below.
