Supposedly, diesel fuel will be refined using less sulphur to make it a bit less nasty for the environment. How much is 'a bit' in this case? Will low sulphur diesel be head and shoulders cleaner than whats currently available? How will it compare to current gasoline emissions?

John Smash!!

Low sulphur diesel has been around for years. The new ultra low sulphur diesel has been created/mandated with an eye toward requiring catalytic converters on diesels. The problem with is that sulphur provided lubrication like tetraethyllead did for gasoline engines. Take that away and refiners have to put in additives to compensate (can you say "MTBE") that could cause other problems.


John

Biodiesel has better lubricity than sulpher, thus it's the natural alternative. There's already many suppliers that mix in 2% biodiesel for their very low sulpher diesel fuel. What sucks is that when hurricane Katrina hit, the EPA suspended a huge number of standards including eleminating the mandate for ultra low sulpher diesel by January 2006. I've seen no word on when they are supposed to meet ULSD now, but hopefully it isn't pushed back more than just a couple months.

The question I have regards the enviro impact of biodiesel. I thought there was a certain amount of naturally occuring sulphur in biodiesel - I might be wrong, just something I remember from high school 4-H - xanthophylls are what gives corn a yellow color and xanthophylls contain sulphur. SO are we accomplishing anything interms of suphur reduction by using biodiesel? I dunno.BUT, I do think that an ultra low sulphur diesel powered hybrid would probably be the most fuel efficient production car ever produced.

Nope. Go here:

http://www.biodiesel.org/resources/f...s/default.shtm

Click on the PDF for emissions. It shows how much cleaner B100 is, including a 100% reduction in sulpher.