I ran across this story a few days ago but it completely slipped my mind until now.  It turns out, Mercedes' upcoming E320 BLUETEC diesel, marketed as the cleanest diesel in the world, failed to meet emission requirements in all fifty states.  Five states - Maine, Massachusetts, New York, Vermont and California - failed to grant Mercedes' newest diesel a passing score, meaning the Bluetec will be sold only in the remaining 45 states.

The announcement came after the results of tests conducted by the EPA in 2004 show an E320 prototype coming in at just beneath 0.06 g/mi of NOx, as opposed to the necessary Tier 2 Bin 5 target of 0.05 NOx g/mi.  DaimlerChrysler remains confident, however, that future BLUETEC models, which will use a urea-based injection system for NOx reduction as opposed to the test vehicle's NOx absorber (a catalytic device that converts NOx to nitrogen), will be compliant with the regulations of all fifty states.

So will it happen?  Will Mercedes' next BLUETEC meet the emission requirements of every state?

It's a bit early to tell.

Currently, the EPA the does not approve the use of urea-based injection systems, a technology that now appears to be necessary if Mercedes does intend to market the cleanest diesel in the world.  The organization promises, however, that they will, in the near future, provide guidance as to how to implement such systems.

When they do, we should have our answer as to whether or not the next wave of BLUETECS will be sold in all 50 states.

As always, we'll keep you posted if we hear anything new. For more info, head over to Green Car Congress to learn more about the Mercedes E320 Bluetec as well as the EPA's test results.