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大型货运卡车不仅外观很酷，而且角色重要。在美国，70％的货运靠卡车。但是，如果跟在货运卡车后面行车，你就知道大货运卡车造成污染。在正常的一年中，美国全部货运卡车排放的二氧化碳量相当于130个燃煤发电厂。

正因为如此，欧巴马政府所提出的新的燃料能效和温室气体标准具有非常重要的意义。新规定致力于做到：

• 防止10亿吨温室气体排放。
• 节约18亿桶石油。
• 削减1700亿美元燃料开支。

这些令人瞠目的数字帮助说明了为什么许多货运卡车制造商、货运卡车队和环保人士都支持今天的能效标准。

美国政府表示，新规定将激发对更高效发动机的开发。虽然开发需要付出不低的成本，但环境保护署（Environmental Protection Agency）相信，交通行业将能在两至六年内收回成本。

环保署以软饮料生产商百事可乐公司（PepsiCo Inc.）为例指出，从2008年到2014年该公司将柴油燃料使用量降低了近四分之一。

正如一家主要柴油发动机制造商的首席执行官对《华尔街日报》(Wall Street Journal)所说，新提出的规定“将帮助我们的产业以一种更可持续的方式发展，这对我们的客户和环境来说是双赢结果。”

Big trucks are cool. And important. They move 70 percent of U.S. freight. But if you drive behind one, you know that big trucks pollute. In a typical year, the United States’ truck fleet emits as much carbon dioxide as 130 coal-fired electricity plants.

That’s why new fuel-economy and greenhouse-gas standards proposed by the Obama administration are so important.

The rules promise to:

• Prevent 1 billion tons of greenhouse gas emissions.
• Save 1.8 billion barrels of oil.
• Cut fuel bills by $170 billion.

Those eye-popping numbers help explain why many truck makers, truck fleets and environmentalists support today’s efficiency standards.

The U.S. government says the new rules will spark development of more efficient engines. That won’t be cheap, but the Environmental Protection Agency (EPA) believes the transport industry will recoup its costs in two to six years.

And EPA can point to companies like soft drink maker PepsiCo Inc., which reduced its diesel fuel usage by nearly a quarter between 2008 and 2014.

As the CEO of a leading diesel engine maker told the Wall Street Journal, the proposed rules “will help our industry grow in a more sustainable way, which is a win for our customers and a win for the environment.”