Flu, CA taxes diesel 8.1 cents more than gasoline, add in about 8 cents a gallon refining cost for Gov. mandated ULSD and you get 16 cents. But, the Gov. mandated ULSD also creates the supply problems that add further to diesel cost:

“The phase-in of the U.S. Environmental Protection Agency’s (EPA) sulfur standards for diesel fuels has the potential to continue to influence diesel fuel prices. The logistics of delivery of ULSD to retail service stations can be a challenge. Most ULSD travels through pipelines on the way to bulk terminals for final transfer by tanker truck to retail stations. Other diesel fuels and petroleum products with a higher-sulfur content in the pipeline, storage, and local distribution systems might contaminate ULSD (jet fuel, for example, can have 3,000 ppm of sulfur). If contaminated, it may not be possible to correct a ULSD fuel batch by blending with additional low-sulfur product, and contaminated batches have to be returned to a refinery for reprocessing, a difficult and expensive problem. Even without potential delivery problems, it costs relatively more to produce ULSD fuel. “ http://www.eia.doe.gov/bookshelf/brochures/diesel/

I guess I should have said fuel taxes AND other Gov. caused expenses.

Yeah, “historically” diesel has been cheaper, just not in recent times. Diesel should be a lot cheaper always as it takes much less processing to make.

Diesel fuel is blessed with a lubricating quality that gasoline lacks. This is one of the reasons behind the success and longevity of diesel engines.

ULSD refines the natural lubricants out and then refiners must add back in chemicals to restore the lubricity. Would any of us be surprised if 5 years down the road we discover the “new” additives pollute more than the natural diesel lubricant they must now refine out?