Mercedes-Benz has been very vague about the timing of the introduction of the much-anticipated 2007 E320 CDi Bluetec. We had been led to believe that the new Mercedes would be 50-state legal. Wrong. We also thought that it would hit the market in September as low-sulfur diesel fuel became mandated state-wide on 1 September 2006. Wrong.

The new target is October 2006 for introduction to the other 45 states. Low-sulfur diesel isn't mandated in the other states until 15 October 2006. However, according to the EPA's clean diesel website, only retail fueling stations that chose to carry ULSD (ultra-low sulfur diesel) have to meet the 15 October deadline. All other retail outlets have until 1 December 2010 to comply. So if you live in one of the other 45 states, make sure the diesel you put in your new diesel gas tank is ULSD!

I'm guessing that the 2007 E320 CDi won't be available to purchase until the end of October. We get screwed again here in California. But it gets worse. The 3.2L V6 direct-injection diesel engine -- with all-aluminum construction, piezoelectric fuel injectors, a variable-nozzle turbocharger with an intercooler and all connected to exhaust-gas recirculation, two catalysts and a particulate filter -won't be available in any form in California. I had some hope that the three Mercedes' SUVs scheduled to receive the engine (ML, R and GL) could be sold in California, but those too will never see the showrooms in here. I couldn't find a timetable for the roll out of the SUVs, but it's likely that they will be in showrooms in the other 45 other states early next year.

As of today, the only diesel engine available in California will be VW's 2007 Touareg V10 TDi. VW has had a fleet of these beasts in the US since June. They were supposed to go on sale at that time; however, one tank of the non-low sulfur diesel fuel made the exhaust belch clouds of gray smoke. It was so bad that at a stoplight, the whole car was engulfed in a cloud and nearby motorists, pedestrians and onlookers all pointed fingers and held their collective noses. The Touareg diesel works just fine with California's new low-sulfur diesel. VW is supposed to have these SUVs in showrooms now. Unfortunately, that's not the case.

I'm told that the V10 diesel Touareg should be in showrooms sometime this month. When, who knows. It makes no sense to me that VW wouldn't have these trucks in showrooms on 1 September. These SUVs have been sitting in some storage facility for months now. California's 1 September low-sulfur diesel mandate was set in stone long before that. As the story goes, VW has only four months -- through 31 December 2006 -- to sell the V10 diesel in California, Maine, Massachusetts, New York and Vermont. As of 1 January 2007, the V10 won't meet new standards and can only be sold in the other 45 states.

VW is supposed to make a big marketing push in California and the other four states to sell as many of the newly-available Touareg V10's as possible. So far, VW has been silent. Why? What's the delay? VW's website, notoriously slow to add new information, is useless (as of the time we publish). In fact, although the car magazines tell us that VW has already substituted the new 3.6L V6 for the older 3.2L unit, the dealer tells me that it hasn't happened yet. So the "new" Touaregs with the updated V6 and cleaner V10 TDi seem to be missing in action. And this is at a time when Touareg sales are in a major slump. The dealers would love to have new models to pitch to customers. This will be the first time the mighty Touareg V10 TDi will be available for sale in California and VW's got only four months to sell them.

After 1 January 2007, there will be no passenger car or SUV with a diesel engine in California. Again. So far, the blame has been placed on the shoulders of the federal Environmental Protection Agency. Mercedes and other manufacturers say they have the technology now to meet or exceed the 2007 level four mandates in all 50 states. However, the system, based on aqueous urea, requires the fluid to be refilled periodically (every 10,000 miles, depending on usage and the engine). The EPA wants to ensure that the fluid replacement happens. The EPA would like the engine to be disabled if the fluid runs out; however, manufactures don't want to have a system that would strand a customer on the road if the tank runs dry while driving. Customers wouldn't want a kill switch like that either. With modern electronics and control modules becoming ever more complex and vexing, having an out-of-control kill switch would definitely alienate a customer.

I hope the EPA stops dragging its feet and trust the customer to get the fluid refilled whenever the car is in for periodic service or whenever the refill light comes on. If the EPA can get past its concerns, the arrival of 50-state legal high mileage clean diesel cars would also open the door for hybrid-electric diesel systems with economy that would blow away the current hybrid champions.

In addition, there would be a significant market for highly-efficient small cars. For example, the Smart ForTwo sold in Canada uses only one engine. It's a Mercedes-designed three-cylinder turbo-diesel engine that gets around 70 mpg. There is a market for that. There is also a huge pent-up demand for luxury diesel cars in Los Angeles. I have no doubt that the Germans and the Japanese could come up with some amazing diesel-powered cars that would get dramatically improved fuel economy over their gasoline-powered siblings.

Ford and GM have these frugal diesel engines in their corporate portfolio; I just don't know if they have the ability to utilize global assets rapidly in the US market. I still can't believe that Ford is unable to figure out how to bring the European Focus to the US profitably. If Mazda can do it with the excellent Mazda3, Ford should be able to do it too.

Honda has already announced its plans to build new diesel engines in the US for the US market. Honda wants to use these high-tech diesel engines (that will meet all 50-state standards) in its passenger cars before the end of the decade (which isn't that far away). If Honda is doing it, you can be sure that Toyota has already studied the idea. Toyota has extremely well-engineered efficient diesel engines in Europe today. If Toyota decides to offer diesel engines in the US, it has the money and expertise to make it happen. So far, Toyota is relying on its hybrid gas-electric technology. But Toyota's flexible enough to add high-efficiency diesel engines to the lineup if management thinks the demand is there.

With the European and Japanese manufacturers seriously looking to diesel technology to increase sales and fuel economy in the US, where is Ford and GM? I'm afraid they may be caught behind again if the EPA and technology permit the foreign competition to enter the market. Please make it happen soon. We want and need clean diesel cars and SUVs in California!