Unique Phenomenon

1engineer · 2012-02-20T17:41:26+00:00

I use RainX windshield washer fluid (the orange color) during winter months. With this fluid I can drive on the interstate at 70 mph in a steady rain without using the wipers. The fluid causes the drops to "run" off and give me a pretty clear view without any wipers. I drove 300 miles in the rain and snow yesterday and noticed something unique to the 4Runner: The aerodynamic shape of the vehicle causes some strange water flow across the windshield. I drew a quick sketch of this action and you will see what I mean. The "dots" are where a water drop will start and the "line" is the direction of flow from start. The view is from the driver's seat. As you can see, all fluid (and airflow naturally) starting in the middle (top to bottom)will flow towards the side of the windshield. Once you get to the middle and above (top to bottom) the air flow goes over the windshield. Probably not much interest but I found it unique.