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Eat at home. And no, takeout doesn’t count. If your lifestyle till now has included more than one restaurant, takeout, or delivery meal a week, then cooking at home will definitely save you money. Leda Meredith is a dancer and writer in New York City. She also teaches botanical courses for the New York Botanical Garden and the Brooklyn Botanic Garden, and has her own horticultural services company, Urban Edens. She is the author of The Locavore’s Handbook: The Busy Person’s Guide to Eating Local on a Budge/ and maintains a local food blog “Leda’s Urban Homestead” at http://ledameredith.net/wordpress. This article appeared on the “Culinate” website: http://www.culinate.com and is reprinted with the author’s permission.

Transportation Clean Diesel

How Diesels Are Different

Diesel automakers have used two technologies to deliver better, sleeker performance: turbocharging and direct fuel injection. Audi and Volkswagen’s clean diesel designation, TDI, stands for turbocharged direct injection. Modern injectors meter fuel quite precisely, injecting diesel fuel into the combustion chamber as many as seven times for each power stroke of the engine. By adding injections at different times — rather than injecting the fuel all at once, as was formerly the case — diesel engines run smoothly and quietly. This also increases fuel economy and lowers tailpipe emissions. Another rub against older diesel cars was that they were

What Makes Diesel Clean

www.GreenLivingPDX.com

By Todd Kaho Whatever notions you have about diesel cars, forget them. Long gone are the days of smelly, black plumes of smoke, noisy engines, slow acceleration, and sometimesfinicky operation. Diesel technology has evolved significantly in recent years, making diesel cars a strong green transportation option. Modern diesel powertrains are quiet, clean, smooth, reliable, powerful, durable and economical. A diesel vehicle will usually cost more than a comparable gasoline vehicle, but the diesel engine’s more robust design means that, with proper maintenance, it should last considerably longer. Plus, some clean diesel cars qualify for a federal tax credit. For generations, diesel power has been the best choice for work-intensive applications, with no other engine delivering as much stump-pulling power. What’s evolved is how the engine compresses and ignites the fuel to propel the vehicle — a change that has capitalized on diesel’s inherent advantages while virtually eliminating the traits that previously made diesel dirty.

slow, with lethargic acceleration that sometimes made freeway merges challenging. That’s no longer true. New diesel cars have a bit less horsepower than their gasoline counterparts, but they make up for that with more torque. Think of torque as the get-up or pulling power of the engine, which impacts how the vehicle accelerates. Diesel engines deliver significant power at low revolutions per minute (rpm), whereas most gasoline engines deliver their best power at higher rpm. So with a diesel vehicle, abundant torque is available right off of idle. Torque is partly why modern diesels are not only powerful, but also fun to drive.

What triggered diesel’s recent evolution was the 2006 federal mandate that all highway-grade diesel fuel sold in the United States have sulfur content of no more than 15 parts per million. Ultra-low sulfur diesel fuel allows automakers to incorporate more sophisticated after treatment devices in the cars’ exhaust systems. Previously, high levels of sulfur in diesel fuel would have poisoned the advanced catalytic converter needed to scrub out pollutants. Modern diesels that use these devices are truly “clean” diesels — meeting even California’s emissions standards, which are the strictest in the country. To publicly demonstrate just how clean and soot-free modern diesel cars are, auto industry representatives hold white handkerchiefs to the tailpipe while the engine is running. Minutes later, the white hanky is still white — not a trace of soot or other emissions. This is made possible by catalytic converters designed to reduce emissions, a particulate filter and, in larger engines, a final catalyst that uses a small amount of ammonia from an injection of urea solution to minimize nitrogen oxide emissions. The diesel particulate filter is an innovative device — it literally traps harmful particulates, and then burns them off, producing carbon dioxide and water vapor.

The Advantages of Diesel

Fuel economy is the primary reason many folks consider diesel. Compared with a similar-sized gasoline engine, a diesel engine delivers about 30 percent better fuel economy,

Columbia River PDX c Green Living Journal d No. 9 Summer 2010

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Green Living Journal Summer 2010 # 9  

"A Practical Journal for Friends of the Environment" Articles: Power Plants of the Future, Recycling Books, Locavore Basics, Clean Diesel, E...

Green Living Journal Summer 2010 # 9  

"A Practical Journal for Friends of the Environment" Articles: Power Plants of the Future, Recycling Books, Locavore Basics, Clean Diesel, E...

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