My sources say there has been a major release of U.S. oil reserves

Oilfield supply company | 20 October 2013 | Mene

[thackney]

Is the SPR filled with lower grade sour grade crude anyway bought at a higher price ?

No. It has a mix of light and heavy, sour and sweet that approximately matches the ratio used in the our nation's refineries.

Actually no better time than now then to get rid of the old crude that was sold at higher price and refill it with a higher grade at a lower priced.

You would have to sell that crude purchased previously at today's prices. Selling it at today's prices so you can buy at today's prices makes no sense.