Cartop Carrier Placement?
#1
8th Gear
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I've just driven two trips with a rather bulky cartop carrier on the roof of my 2012 RX450h, and am wondering about the best placement -- far forward, or far back? My first trip was with the carrier farthest forward, one pad touching the moonroof; for the recent trip I set it a bit further back, worried that the pad might damage the moonroof. But the recent trip's positioning seemed to cause more wind noise.
Aerodynamics can be mysterious: is it better for the carrier to be far forward? or far back? If nothing else, my next trip will try placing it far back, to see what happens. But I would appreciate some knowledgeable advice. Any aerodynamic engineers out there?
Aerodynamics can be mysterious: is it better for the carrier to be far forward? or far back? If nothing else, my next trip will try placing it far back, to see what happens. But I would appreciate some knowledgeable advice. Any aerodynamic engineers out there?
#2
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It seems you are the one who is running controlled experiments.
Please share what you find out ... also if you could record mpg impact.
Thanks,.
Salim
Please share what you find out ... also if you could record mpg impact.
Thanks,.
Salim
#3
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Do you have a pic? Wondering why it was touching the moon roof - was it resting in between the roof rails or was it attached on top of the cross bars and part of it dipped down onto the moonroof?
#4
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sorry, my original post should have had more detail: the carrierbox straps attach to the side rails, but with weight in the box it rests on the roof (rubber pads on the bottom of the box). Thus when driving over bumps it can bounce slightly and thus also wobble slightly in the wind. As I write that it sounds flaky, but it has worked well -- my concern is with laminar flow of the air, to reduce drag and reduce noise (I presume they are correlated).
Gas mileage is slightly affected -- from 26mpg without the box and 24mpg with the box, so far.
Gas mileage is slightly affected -- from 26mpg without the box and 24mpg with the box, so far.
#5
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sorry, my original post should have had more detail: the carrierbox straps attach to the side rails, but with weight in the box it rests on the roof (rubber pads on the bottom of the box). Thus when driving over bumps it can bounce slightly and thus also wobble slightly in the wind. As I write that it sounds flaky, but it has worked well -- my concern is with laminar flow of the air, to reduce drag and reduce noise (I presume they are correlated).
Gas mileage is slightly affected -- from 26mpg without the box and 24mpg with the box, so far.
Gas mileage is slightly affected -- from 26mpg without the box and 24mpg with the box, so far.
I have been with RX first gen ever since they were produced. The early ones had rubber stripes on the roof from front to back. Owners thought the roof tops were rugged and luggage can be put on the stripes [like vehicles that used to run around in Safaris]. Lexus sent out corrective circulars and the straps were removed.
Salim
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