"In general, the processing required to reduce sulfur to 15 ppm also reduces the aromatics content and density of diesel fuel, resulting in a reduction in energy content (BTU/gal).
The expected reduction in energy content is on the order of 1% and may affect fuel mileage."

That is a quote from one of the diesel fuel producer's web site.

Apparently I am not dreaming that as the switch to low sulfur fuel takes place I am losing mileage.

Further, JPJ sent me a link on bio-diesel and biodiesel has a substantially lower BTU content (around 8%) with blends having somewhat less of a negative impact.

Maybe it is just me, but everytime the tree huggers and the government come up with solutions to problems it just strikes me that the solution is worse than the problem.