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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The entrance of West gas into Shanghai has made it a double-gas supplied city.

前言： 随着“西气”进沪，上海形成了“东、西”双气源供气的格局。

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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.

FORBES: Who Wins More From The Google Car: Cities or Suburbs?

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

FORBES: Brownout