当你与工程师谈论起未来汽车行业“前景与未来”时，自动化往往已经成为了你们之间的最热话题。但是，最后还是把谈论焦点会转回柴油发动机，我们有时会不禁要扪心自问：“难道柴油机真的已经日薄西山了吗？”

正是由于人尽皆知的大众汽车“尾气门”事件，导致宝马（BMW）与奔驰在业务上也受到了牵连，导致其几乎完全砍掉了在美国市场的柴油发动机产品线，而欧洲市场业务也是深陷泥潭。

马自达宣布在汽油发动机方面的创新突破，计划将于2019年将推出压燃点火汽油发动机，并提供未来构建轻混合动力汽车组合的可能。如果该发动机能一下子提升40%的热效率，并拥有混合动汽车无法匹敌的扭矩，请问有谁会对此忍心说不？至少，福特动力总成首席工程师Pete Dowding是这么认为的。

Dowding当然也承认柴油发动机目前所受到的“重创”，但是他同时也看到一个广阔而蓬勃的卡车市场。在这个领域，柴油发动机依旧能延续传奇。Dowding透露，福特卡车的买家正热切盼望着明年春天上市的搭载3.0升V6柴油发动机的F-150。正是由于受到排放门阴影的影响，菲亚特克莱斯勒被美国环保署禁售的柴油车，通过减排系统的修改优化后美国环境保护署（EPA）已经向其颁发了许可证。同时旗下公羊品牌搭载了柴油发动机的非常受欢迎的轻型皮卡也已重新上线，同时也包括Jeep大切诺基。

但不可否认的是，在北美发生的大众“尾气门”丑闻已经波及到了欧洲汽车市场，即便是柴油发动机最坚定的大陆集团也开始秉烛探索新的动力科技。在过去一段时间内，一些大城市对柴油机纷纷发布了限令，将纳入了相关法规，而英法两国则已经直接提议要在2040年之前全面禁止内燃机车辆的销售。

而这一浪潮在素有“压燃技术摇篮”之称的德国也未能幸免，在那里，柴油发动机不仅在前瞻性技术中不受青睐，而且还在与迅速崛起的电动化技术的战役中败下阵来。今年夏天，德国汽车制造商召回了多达500万辆柴油车，并对发动机管理软件进行了升级，从而使氮氧化物（NOx）的排放能符合如今的欧盟六项规定，同时计划拿出5亿欧元对老旧汽车进行现金补助，鼓励更换排放更低的新款车型，以此改善城市空气质量。

而作为“柴油派”的一员，宝马主席Harald Krüger则认为，“柴油发动机原本是一项尖端技术，不仅高效，而且广受客户青睐，但近两年来，却遭受到了故意诋毁和公开质疑。由此，数百万驾驶者陷入了巨大的迷茫之中，而我们也不知未来将去向何方”，这番言论似乎也是在为柴油机的回归寻找理由。

BMW宝马公司董事长Harald Krüger先生则表示需要回归理性，他认为：“柴油发动机原本是一项尖端技术，不仅高效，而且广受客户青睐，但近两年来，却遭受到了故意诋毁和公开质疑。由此，数百万车主陷入了巨大的迷茫之中，而我们也不知未来将去向何方”

事实上，德国的各家汽车公司已经在不遗余力地挽救柴油发动机了。这其中，不仅要应对政客们目光短浅的煽风点火，还要面对影响日增的“电动派”言论，比如“电池电动技术即将迎来全盛时期”。德国总理默克尔在9月接受彭博采访时曾说，“我们需要牢记并纠正错误”，不过同时，她也强调，“（但）这并不意味着我们就要彻底剥夺柴油发动机行业的未来。”

博世（Robert Bosch ）Mobility解决方案的主席Rolf Bulander博士在8月的一次媒体活动上告诉记者，2025年后，柴油发动机依然将是民用车辆最主要的动力能源之一。

“巴黎、马德里、雅典以及墨西哥城纷纷决定，从2025年起，禁止柴油发动机车辆上路。这些政策的盲点在哪里？在我们看来，这是被生态保护带偏了，或者至少说是一种‘盲目的’环保措施。说盲目是因为这样的驾驶禁令完全忽视了柴油发动机突出的节能高效性，而这对控制全球变暖依旧十分必要。而说它盲目的另一个原因，则是它低估了柴油发动机技术依旧有待挖掘的发展潜力。”

这些观点都对。不过，毕竟柴油发动机在尾气排放上的问题依旧存在。所以答案就是：与其选择逃避，不如迎难而上。

或许本田为我们带来了解决方案，由本田专为欧洲市场设计的全新款1.6升iDTCI柴油发动机成为了世界上首款通过全新WLTP测试循环（Worldwide HarmonizedLight-Vehicle Test Procedure）认证的发动机。真实工况驾驶排放（RDE）测试数据则是该WLTP测试最重要的数据来源之一。

没错，正是这项测试让大众排放舞弊案浮出了水面。

本田十分谨慎地表示，这款新型的柴油发动机采用了一些巧妙的强化设计，才使得此款发动机在真实工况驾驶排放测试中获得了这一亮眼的成绩，“我们使用了一款全新的氮氧化物存储转换（NSC）系统，配备了更多的催化剂及更高含量的贵金属（银、铂及钕），能将氮氧化物气体存储至再生循环。”

如果你想估算“增加的成本”，那答案无疑是远超其他同级别设备。

不过，在我们能够降低后处理成本，或者有创新型的内燃机可以实现大幅减排之前，“柴油派”最好的选择或许只能宣传在真实工况驾驶排放测试上所取得的好成绩了。

宝马的Krüger表示，“毫无疑问，未来的交通运输仍然将依赖性能最优的柴油发动机。”

对此，我并无异议。不过，为了不被“打脸”，我还是希望汽车从业者们现在就要行动起来，早日实现柴油机研发的重大突破。选择这条路并不是因为它平坦宽阔，而是因为汽车人从不畏惧艰险。

Start talking car-business “big-picture” with engineers and once you hash out autonomy for the thousandth time, the discussion invariably comes to diesel. Is diesel stick-a-fork-in-it done?

Everyone knows the Volkswagen impact, which for now has caused diesel compatriots BMW and Mercedes-Benz to almost completely withdraw diesel models from U.S. showrooms. The VW scandal generated plenty of still-fomenting blowback in Europe, too.

But even with pressure from ongoing gasoline-engine design innovations—Mazda just announced it is ready to launch a production compression-ignition gasoline engine in 2019, for example, and there’s a growing menu of hang-on electrical enhancements—diesel doesn’t quite look dead. After all, what car company can turn its back on 40% thermal efficiency that comes as easy as falling out of bed in the morning—bundled with the luscious, customer-pleasing torque a hybrid can’t hope to match?

Ford powertrain chief engineer Pete Dowding is talking the talk, at least. He concedes diesel’s battered at the moment, but he sees a strong, high-volume truck market where diesel’s still a magic word. Ford truck buyers, he said, are hungry for the coming 3.0-L V6 diesel for the F-150 next spring. And after an emissions-scandal scare of its own, FiatChrysler sold the EPA on an emissions-system reprogramming and FCA’s Ram brand is back in business with its popular diesel for light-duty pickups (as well as the Jeep Grand Cherokee).

But there’s no denying the diesel pandemic that Volkswagen started in the U.S. has bled to Europe and even the famously diesel-worshiping Continent has picked up the torches to pursue the Frankenstein monster. Several large cities have outright bans on the books or in play. Britain and France took a larger view, proposing to prohibit all internal-combustion vehicle sales by 2040.

Even in Germany, the cradle of all things compression-ignition, diesel might be losing not just the perception war—but the battle with fast-moving electrification technologies, too. Late summer saw German automakers in a desperate-looking, Cash for Clunkers-mimicking gambit to tweak the engine-management software of up to 5 million vehicles to bring oxides of nitrogen (NOx) output in line with today’s Euro 6 regulations. Oh, and a €500-million fund to improve urban air quality.

Seemingly calling for a return to reason, BMW Chairman Harald Krüger was quoted as saying, “For almost two years now, diesel technology which is cutting-edge, highly-efficient and popular with customers has been deliberately and publicly discredited. This has caused tremendous uncertainty among millions of drivers and it’s not going to get us anywhere.”

Indeed, Germany Inc. is working hard to protect the diesel, not only from short-sighted political knee-jerk but also from the expanding notion that battery-electric technology is ready for high-volume primetime. Germany’s Chancellor Angela Merkel was quoted in September by Bloomberg as saying the onus is on the country’s entire auto sector to “address unforgiveable mistakes,” but she stressed, “that doesn’t mean we have to rob the whole industry of its future.”

Dr. Rolf Bulander, chairman of Robert Bosch Mobility Solutions, told journalists at an August media event that he sees the diesel as a core power source for passenger vehicles beyond 2025.

“What is amiss when Paris, Madrid, Athens and Mexico City decide to ban diesel vehicles from their streets from 2025? In our view, this is ecologically misguided—or, at best, environmental protection from a ‘blinkered’ perspective. Blinkered if only because such driving bans ignore diesel’s outstanding efficiency, which is still needed to limit global warming. But, also, blinkered because it underestimates the potential still latent in this technology.”

All well and good. But there’s no question diesel’s emissions-perception problem isn’t going away. The answer: rather than run from it, embrace it.

Leave it to Honda, perhaps, to adopt exactly that approach. The engine experts there recently crowed the new European-market 1.6-L iDTCI diesel was one of the world’s first engines to be certified under the watch of the newly-adopted Worldwide Harmonized Light-Vehicle Test Procedure (please just say WLTP). A crucial component of the WLTP is data input modeled from on-the-road emissions testing widely known as real-world driving emissions (RDE).

Yes—the very same scrutinizing that exposed VW’s cheating.

Honda carefully admits its new diesel achieved its exceptional RDE results with some slick engine-design enhancements and, uh, “a new NOx Storage Converter (NSC) system with larger catalysts and a higher content of noble metals (silver, platinum and neodymium) that store nitrogen oxide gas until the regeneration cycle.”

If you’re reading “added cost,” go to the head of the class.

But until aftertreatment expense can be reduced or a combustion innovation improves engine-out emissions, the best thing the industry can do is to keep bragging about acing those new RDE tests.

“Future mobility will definitely depend on state-of-the-art diesels as well,” BMW’s Krüger declared.

I agree. But just to be on the safe side, get cracking on the next big diesel breakthrough, car industry. Do it not because it’s easy, but because it’s hard.

Author: Bill Visnic
Source: SAE Automotive Engineering Magazine