Window Deflectors

I have the weathertech on my 2006, and still get that booming sound with just one window down. Good luck.

 

The Prius, like other aerodynamic cars, has trouble with airflow oscillations over open windows. It's part of the price you pay for getting good mileage. It's also a good reminder of why you get better mileage at speed with the windows closed. If you do insist on driving at speed with open windows, I find it works well to open the back windows about half way down, then adjust the front windows as needed. It takes a little playing around to get it right, but you can eliminate most of the booming.

Tom

 

Even non-aerodynamic vehicles boom. The anti-Prius, for example, did (it was a 2001 Nissan Pathfinder, definitely not aerodynamic). You are making a whistle when you open a side window. The whistle resonates at a very low frequency (a few Hz) because the volume of the car is so large. The vehicle I owned before the anti-Prius was a 1990 4Runner. It would also boom, but I could stop it by opening the hatch glass an inch or so (power rear window). It "leaked" out the air and damped the resonance.

My side window deflectors (the other brand sold by Toyota as a Toyota part here in Canada) have no effect on mileage that I have been able to discern. When the windows are only down a bit - that is, still at least at the level of the lowest point of the deflector, there is no booming and not too much wind noise.

 

No, the window deflectors won't help for that problem. They're great for opening the windows a bit in the rain without getting wet, but the air still booms. I'm not sure how much more of a problem this is on a slippery car, because my 1966 Plymouth had the same issue - among others - and it was most definitely not aerodynamic. I've had other cars with little triangle windows either front or back that could be opened, and they were wonderful for being able to vent the cabin without any buffeting. Maybe the rear porthole windows on the 2010 Prius could have hinges, weather seals, and a dash button to pop them open and closed?...hint...hint. Come to think of it, they'd be good for venting excess heat while parked, too.

 

Does anyone know if they have a set of deflectors that will fit on the 01?