Re:<"Why would they be doing this? Does this defeat the purpose and waste time and resources? Why not make OD 66 all the time?">
...or if you want the shorter version, OD-66 is 33% regular diesel, 50% biodiesel (not USSE's), 15% ethanol (again, not USSE's) and only 1% USSE's pyrolysis oil. That means even if pyrolysis oil cost $0.00/gallon, they could only produce fuel 1% cheaper than everyone else can--and that assumes they don't get a 1% decrease in performance by adding the pyrolysis oil. Of course ask any optimist here and they'll say the pyrolysis oil greatly enhances the fuel somehow. Ask them for a link, though, and they will all come up short.
Some might point to AmSpec's testing which shows a comparison to Ultra low sulfur diesel but that's a worthless comparison. Here's what USSE says in their PR...
"In a report published today on the USSEC Research page, results included improved flashpoint, higher viscosity, dramatically lower sulfur (ppm), less copper corrosion, higher cetane index, dramatically less carbon residue, and improved lubricity over conventional Ultra Low Sulfur Diesel."
So, what's a good reason to choose Ultra Low Sulfur diesel as a comparison...
Lubricity: Lubricity is a measure of the fuel's ability to lubricate and protect the various parts of the engine's fuel injection system from wear.The processing required to reduce sulfur to 15 ppm also removes naturally-occurring lubricity agents in diesel fuel. To manage this change the American Society for Testing and Materials (ASTM) adopted the lubricity specification defined in ASTM D975 for all diesel fuels and this standard went into effect January 1, 2005. The D975 specification is based on the High Frequency Reciprocating Rig (HFRR) test (D 6079) and requires a wear scar no larger than 520 microns.
Energy Content: 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.
Cetane Number: In general, the processing required to reduce sulfur to 15ppm also reduces the aromatics content resulting in an increase to the cetane number.
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...and this is for a fuel which contains only 1% of Rivera's pyrolysis oil. You can ask yourself why the company never does any meaningful comparisons. I have my own opinion.