Let's Stop Defaming Diesels

They're no longer reeking and fume-belching hazards to the environment. Sadly, though, laws restricting these fuel-efficient machines remain in effect

You would be hard pressed to find anyone who doesn't want win the war against foreign oil dependency. It doesn't matter if your kid is trudging through Arabian sands shouldering a rifle, or if you are still recovering from the shock of that last $100 SUV fill-up. What we all have is a shared goal to kick that oil-import habit, or at least get it under control.

It's war in the truest sense, but we are entering it with one fuel nozzle tied behind our backs. Politicians and celebrities appear to have anointed the gas-electric hybrid as the one and only new power-train technology. That view is shortsighted and removes from the debate another potential alternative: clean diesel.

Why is there a lingering resistance to diesel engines in passenger cars? Has the Environmental Protection Agency (EPA) set an emission standard so high that development and manufacturing costs will outweigh the benefits of diesel? The answer, in part, could be historical. Some activist and legislator views of Dr. Rudolph Diesel's invention are eternally tarnished by 30-year-old visions of soot-pewing dump trucks motoring along our roads.


  But that's no longer the case. Today's clean diesels use electronic engine controls, direct fuel injection, and turbo charging to extract efficient power from smaller-displacement engines. Auto manufactures will gladly tell you that it's easier and less expensive to wring out more miles per gallon from a diesel than from a comparable gas engine.

Europeans already have signed on to the oil-burner bandwagon. Thanks to their fuel-sipping nature and tax advantages, diesels dominate the European market. Sixty percent of the luxury cars offered on the Continent are diesel, and there are numerous compact cars that can top 70 mpg on the highway.

I have road-tested virtually all the diesel vehicles available to most U.S. citizens. I add the "most" proviso to cover residents of New York, Massachusetts, Vermont, Maine, and of course, California. Those states have adopted the current California Air Resources Board (CARB) regulations that ban the purchase of these cars, including everything from the 44mpg Golf TDI to the luxury Mercedes E320 CDI that's rated at 37 mpg highway. In the case of the E320, you would be hard pressed to know that you weren't driving a gasoline-powered car, given its smooth idle and excellent off-the-line acceleration.


  While New York and Massachusetts will not allow you to register a new diesel car, Maine will let you license a diesel sedan provided it was bought new out of state or purchased used from an in-state dealer, but only if there are 7,500 or more miles on the odometer. Hmm, seems a bit arbitrary don't you think? By the way, diesel-powered pickups and vans are exempt from those restrictions.

The Volkswagen, Mercedes, and other modern, clean diesel vehicles meet every CARB emission standard except for nitrogen oxide. That issue should be resolved when low-sulfur diesel fuel is readily available sometime in 2007.

You would think the problem had been solved. Well, not exactly. The EPA, CARB, and others have developed new and incredibly stringent emission regulations which target "greenhouse gases" like carbon dioxide. In the case of the EPA, it's something called the Tier II Bin 5 standard, which goes into full effect in 2009. While its name sounds like a piece of furniture you might find in an IKEA catalog, auto manufacturers will need more than a screwdriver and pliers to assemble cars that pass this test. Particulate traps and other expensive technologies will have to be developed quickly.


  The new regulations have made domestic and import manufacturers a bit gun-shy about rolling diesels into the US market. However, at the recent Detroit Auto Show diesel manufacturers were on the move. Mercedes showed its BlueTec diesel technology that will be able to be sold in all 50 states and can be adapted to meet the tougher 2009 emission standards. Look for a full portfolio of vehicles including the large GL SUV, and the high-end S Class. Toyota, Nissan, and Honda also signaled their diesel intentions.

A few things need to happen in the near future to encourage more diesels on U.S. roads. The EPA and CARB have developed the new emissions standard, now is the time for them to stop tinkering with it and let manufacturers continue to come up with technological solutions.

Don't make emissions a rolling road block that discourages product development. Any particles or substances released into the air that have not been sucked up, absorbed, or otherwise destroyed by the on-board emissions systems will be offset by the increased fuel efficiently of the diesel vehicles. Less fuel burned means less fuel that has to be refined, which means less pollution.


  Manufacturers have to share development costs and technology for particulate traps and other devices in order to meet Tier II. This already has happened with hybrid technology, so there is a precedent. Existing advanced European power plants should be imported. All large, truck-based SUVs should offer the diesel option -- perhaps a V6 diesel would be suited for this purpose. Smaller diesels would also be useful in popular light pickups, still the best selling vehicles in the U.S.

And finally, all of us who yearn for freedom from foreign oil must remember that the solution is not found in gas-electric hybrids alone. No, what we need is more like a tool box with a full set of wrenches, screwdrivers, and sockets. Our tools to become independent of foreign oil must include clean diesel, gas and diesel hybrids, electric and hydrogen power, and any other technology that might appear in the future.

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