Known as 'hypermiling', the method can double gas mileage.

这种方法被称为“超速行驶”，它可以使加油里程增加一倍。

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But until they are widely available, simple changes to the internal combustion engine-and the way we drive-could as much as double gas mileage.

但是，在这些汽车还没有广泛使用之前，对内燃机简单的改变以及我们驾驶方式的改变能使汽油里程加倍。

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Double the tax, and gas would remain competitive with nuclear and wind power, too, says Exxon Mobil.

把税提高一倍，天然气就能和核能和风能竞争，埃克森美孚称。

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Can General Motors create a hybrid Hummer and exclaim that eight miles per gallon is "Double the gas mileage!"

FORBES: Magazine Article

This means that density would double if gas prices doubled.

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If we assume natural gas prices track oil's, gas will double from today's already high level.

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