Questions on diesel emissions

If "dirtier" Volkswagens were allowed, and fullsize diesel SUVs not - the total emissions would certainly be less.

If the true concern was total emissions - we'd be putting limits on frivolous air travel. And one of the worst polluters into the upper atmosphere is the space program. Also, going back to depending more on rail shipping instead of road tractor-trailers would cut down a huge amount of emissions.

By the way - we've got two 91 Volkswagen Jetta diesels. No turbos, mechanical injection, etc. Both consistently get 45 MPG (U.S. gallons) and have gotten up to 51 MPG on rare occasions. Both also get a consistent 38 MPG "around town and up the mountain."

Also have two 1981 Chevy Chevettes with 2.2 Isuzu diesels that do almost as well.

Volkswagen diesel was only 48 state compliant and pulled out of the diesel market in the U.S.

Heavier diesel vehicles had more relaxed regs.

Currently New York currently will not register any new diesel-powered passenger car on account of emissions. So except for an occasional ancient Benz there are virtually NO diesel cars running around here right now.

In addition the CHEAPEST diesel fuel in upstate NY is currently $3.65 - almost half a buck more than than regular gas. So diesel car mileage would have to be dramatically better than an equivalent gasser in order to make a diesel option attractive right now. It's crasy....

(Incidentally at $3.65/gal I'm driving my F250 diesel as little as possible these days!)

For early 2008 the Mercedes diesel is also not allowed in California and Pennsylvania, Connecticut and Rhode Island -and maybe Maine, Massachusetts, and Vermont - but it's confusing.

Mercedes states that by mid-2008, their diesel will be 50 state compliant. Same with Honda and Volkswagen.

In regard to diesel fuel prices - yeah - I wonder why diesel is so much higher than reg. gas now - since it used to require less refining, not more. I wonder how much expense has been added with the ultra-low sufur treatment.

My neighbor, who has agricutural plates on his truck - is driving everywhere on dyed farm-fuel.
He claims that as a farmer he's allowed. I believe he's in error. Kind of funny though - he has two diesel trucks. A 93 Dodge-Cummins and a 2006 Duramax. The Duramax won't run on the farm -fuel, only the Dodge will. Seems the Duramax has pump-drivers that force the system into "limp mode" when it senses farm-fuel or heating oil.

The Ford Excursion - essentially an oversized SUV assembled on the F250 frame - got around passengler vehicle emissions limits on account of it's weight. It's max GVW was something like 8,500 lb GVW if I recall. This classified it as a light truck, thus subject to less stringent emissions requirements.

Incidentally Ford ended production of the Excursion in 2005. AFAIK there is no factory diesel-powered Navigator or Escalade.