Thread: urban myth?
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Old 04-12-2008, 07:30 PM   #7 (permalink)
WereBo
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Re: urban myth?

It's to do with airflow and slipstream. It only makes a noticeable difference when you hit about 50MPH or over.

It's the same if you have a roof-rack mounted, they can add up to 40% fuel usage, especially if loaded with luggage etc. That's why you see folks covering the luggage with plastic sheeting etc. It not only keeps any rain off, it smooths the airflow somewhat.
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