The units run on natural gas which gives them about 48 percent efficiency overall. Smaller natural gas fuel cells are already being marketing in Japan.

该电池单元使用天然气，这将会提供约48%的能效。稍小型的天然气电池正在日本市场出售。

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Thepetrol engine is optimally sized to provide the cruise power at its most efficient operating point, resulting in an improved fuel efficiency overall.

航空煤油发动机的尺寸经过优化设计，已经能够在发动机的最有效的操作点上提供巡航动力，进而从总体上提高燃料效率。

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But only if they operate at near capacity, otherwise, their overall efficiency is poor.

但只能是在它们接近满负荷运转的情况下，否则整体效率就会很低。

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We drove eight cars in and around New York City to critique them for style, performance, efficiency and overall practicality.

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Those engines typically have less than half the overall efficiency of diesel engines.

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Furthermore, by capturing and reusing energy that would otherwise be lost in waste-heat, CHP improves overall efficiency by double digits.

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