Ergons price revision had called for a 10 to 17 cents per gallon decrease, effective Aug. 27, with the lighter products edging down more than the heavy oils. The refiner also explained that other adjustments had been made based on end-use application and discounts that were previously in place.

In recent weeks, there have been several price adjustments prompted by falling crude oil prices and slowing seasonal demand. While there had not been any official notification, it was heard that a number of naphthenic suppliers had adjusted prices down by up to 20 cents/gal for select accounts throughout the month of August.

Market participants expressed concern at the sharp swings that crude oil values experienced over the week. West Texas Intermediate prices jumped from lows near $38 per barrel a week ago to around $49/bbl Monday then fell again Tuesday on weak Chinese manufacturing data. WTI closed on the CME/Nymex at $45.41/bbl on Sep. 1, up $6.10/bbl from its Aug. 25 settlement of $39.31.

Brent was trading around $49.56/bbl on the CME on Sep. 1, up $6.35/bbl from $43.21/bbl a week earlier.

Whether the higher crude values can be sustained remains to be seen, as steeper oil prices are likely to encourage more drilling and cracking in the United States, an industry insider explained.

In the meantime, the spike in oil prices appears to have lent a stabilizing effect to paraffinic prices, as no further posted price decreases were heard since a recent round of cuts.

Producers reported fairly steady demand for most base oils, with heavy-vis products still enjoying heightened buying interest and stable pricing as compared to low-vis products.

Within the Group I category, consumption of bright stock in particular remains strong. This cut remains tight, and pricing is holding up very well, one producer confirmed.

Sellers acknowledged that appetite for light- to medium-vis cuts had weakened somewhat and that the recent price decreases had done little to encourage additional orders. Lighter grades were described as generally long, and many spot movements have been taking place within a $1.70-1.80/gal range, which reflects fairly soft conditions, sources said.

While there are some signs that domestic business has started to taper off ahead of the Labor Day weekend and the end of the summer, buying interest in Mexico has been fairly steady. This could be partly attributed to production issues at the base oil facilities of the local producer, Pemex, over the past month, sources explained.

Among developments that could affect U.S. production, the catalytic dewaxing unit at Calumets base oil plant in Shreveport, La., will temporarily close for 15 to 20 days of maintenance beginning the second week of September. The plants solvent dewaxing unit will undergo a turnaround in October. The catalytic dewaxing unit is part of a Group II stream, while the solvent dewaxing unit is part of a Group I stream, each of which has capacity of 4,000 b/d.

There were also unconfirmed reports that Motiva would be postponing a turnaround at one of its three trains in Port Arthur, Texas, from its original date in October to the first quarter of 2016. The Motiva base oil plant has capacity to manufacture 40,300 b/d of Group II base oils.

Historic U.S. posted base oil prices and WTI and Brent crude spot prices are available for purchase in Excel format.