I'm thinking of buying a new diesel truck. A friend advises me to buy a 2006 model instead of the 2007 because of the new emissions laws for the 2007 models. Advice?

I agree and did. The Jan. 07 emission laws can make the cost of the new ultra low sulfer diesel engines at least $2000 more in cost and will have particulate treaters that will take some user imput. And we all know not to buy the first year of major change.

Chevy Silverado has a 2007 "classic" series that appear to have the same diesel as the 2006 models. Do you know if that is true and if so how long the classic series will be available?

Yes the 07 in the HD is the same as the 06 truck. The new GMT900 platform truck in HD 2500 and 3500 won't come out until January or February and will be called a 2008 model. The 1/2 tons with the new body style should be for sale the end of October. So the old style 07 HD's should be avaliable for a least 3 or 4 months.

Don't know when GM will shut them off, but they may end them early to force folks to buy the new model. But remember the New 08 HD's in GM and SD's in Ford diesels and late built Dodges diesels will need the Ultra Low Sulfer diesel. Which is suppose to be availible at 80% of the stattions by January, but you won't be able to use Low Sulfur diesel in the new diesels without damaging part of the new particulate filters required in diesel engines built after Jan.

Will the 'older' (early 2007 and 2006 back) diesels run ok on the new ultra low sulfer diesel, or will we start to have a harder time finding fuel?

Supposedly the new Ultra low diesel has the additives to work with the older diesels. But they said that about unleaded gas too in the late seventies. Some older diesels could get worse mpg and may leak engine oil some. I think it's 2010, there will only be Ultra low diesel. So we can't stop it. Might be a good time to research additives.

After reading above, it sounds like a 2007 Chevy Silverado 'Classic' still has the 2006 engine. Does that mean it will run properly on Low Sulfur Diesel, or will they also require the Ultra Low Sulfur Diesel?

Yes the 07 Classic will run on low sulfur diesel and the normal diesel motor oil not CJ4, the more expensive oil for the Ultra low sulfur fuel engines made after January 07