If you're in trucking in California leave now-It'll get nasty
I just attended the Great Western truck show in Las Vegas and the CTA (California trucking association) put on a 2 day seminar about the new smog rules for diesel engined vehicles 16,000 lbs and over. This will also include a lot of things you don't think about- diesel generators-refer units (like on semi trailers)-lots of stuff.
You won't like the first part-If one has a engine with EGR (2003-2006) you can now convert that baby to the new specs for $25-30,000. They're doing them now.
If you're fortunate to have one thats a 2007-2009 you can get away with a $15-20,000 upgrade.
If you're older than 2003 those vehicles basically will be phased out by 2014-2015 unless you're updating your fleet with newer units that give you "credits" towards your total fleets numbers.
Those with three or less units basically get a extra three year window to upgrade.
Now the good news-RV'S are exempt for now. Sometime in the next 5 or so years you'll see many of these dirt haulers and local guys just vanish. The outcry will be so loud I wouldn't be surprised to learn of some of the rules being pushed back but you never know. Just thought you'd like to know.