On Sat, 1 Nov 2008 22:55:07 -0400, "Garland Gray"
wrote:

Since this is the fuel (most likely) in our tanks now, are there any
different measures needed for winter storage ?

It was suggested to me that ULS diesel fuel deteriorates more rapidly, so it
was better not to top off the tank, but to fill in the spring with fresh
fuel, and deal with any moisture/water then.

However, my local fuel oil supplier said he hadn't heard anything about a
short shelf life for ULS diesel.

Anyone know anything about this ?

Actually yes.

Sulphur is found in crude in various quantities, from negligible,
i.e., sweet crude, to much larger percentages, sometimes, depending on
the form of the sulphur, to the extent that the fumes coming from the
crude are poisonous, sour crude.

Refinery people are very aware of the problems of having sulphur in
any quantity in either crude, gas, or refined products and use various
processes to remove it.

In diesel oil the traditional test for the amount of sulphur is
measurement by a "copper strip test" which measures the corrosion of a
copper strip over a 3 hour period.

Of course, environmentalists are also aware of the undesirability of
sulphur in fuel and have legislated percentages downward.

Thus low sulphur diesel is simply oil that has had a larger percentage
of sulphur removed from it. It is still composed of the various
hydrocarbons that normal diesel is composed of, but with less sulphur
then previously.

Use of low sulphur diesel produces less corrosive substances in the
engine, less air pollution and slightly less lubricity -- sulphur may
have some lubricating qualities, depending on the form it is in.

Since sulphur in a hydrocarbon product is a contaminant, removing it
will not have any effect on the storage of the product, except less
sulphuric acid will be formed in the sludge.

Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)