Add one more in what's becoming a string of ugly quarters for independent refiner Frontier Oil (NYSE: FTO). Yet these disappointing results could soon come to a halt, yielding to the type of outperformance that shareholders are used to.

For the first quarter of 2010, Frontier lost $40.3 million, which works out to $0.39 per share. In the year-ago period, the company earned $0.56 per share. However, results did improve from the previous quarter, thanks to more favorable market dynamics.

And Frontier fell with the rest of the best. Fellow independent Tesoro (NYSE: TSO) also reported a loss. Holly (NYSE: HOC), whose refineries are geographic cousins to Frontier's, failed to post profits, too. Even ExxonMobil (NYSE: XOM), which has a reputation for running low-cost, flexible refineries, wasn't able to cook up profits in its U.S. downstream business.

In fact, when it comes to U.S. refining, it appears that the only place to hide in Q1 was in Chevron (NYSE: CVX), although I have my doubts even here, because the company's higher-earning chemicals division may have concealed refining losses (Chevron lumps together chemicals and refining operations as "U.S. downstream").

Going forward, however, the picture decidedly brightens. In April and so far in May, crude oil differentials widened substantially, which bodes well for Q2 profitability. Also, by the end of the quarter, management had wrung out $1.50 per barrel in refining gross margin at the Cheyenne facility, roughly marking the halfway point to its ultimate efficiency target.

All of that noted, I caution investors against wild bullishness. Some of the recent improvement in product margins stems from temporary maintenance-related shutdowns across the industry. In terms of other big-picture dynamics, Frontier management aptly cautioned:

"we will need a continuing recovery in product demand to absorb high refined product inventories and the potential production from underutilized industry capacity."

For those who've been following my industry coverage, that should sound strikingly familiar.

Fool contributor Mike Pienciak holds no financial interest in any company mentioned in this article. Try any of our Foolish newsletters free for 30 days. The Fool has a highly refined disclosure policy.