New York's main contract, light sweet crude for delivery in September, fell 15 cents to $82.32 a barrel.
Brent North Sea crude for September delivery shed two cents to $82.18.
Oil markets were hit by data released by the US Department of Energy late yesterday showing a sharp increase in US distillate and gasoline inventories even as crude stockpiles fell more sharply than expected, analysts said.
"Oil prices fell slightly as positive economic data was outweighed by a larger-than-expected increase in US distillate inventories and an increase in gasoline inventory," said a Commonwealth Bank of Australia report.
The report showed gasoline stocks rising 700,000 barrels last week, compared with average expectations of an 800,000-barrel decline in a Dow Jones survey of analysts.
Distillate inventories, including heating oil and diesel, also rose 2.2 million barrels, double the expected gain.
The fall in oil prices flew in the face of a sharper-than-expected fall in American crude stockpiles, which fell by 2.8 million barrels, double the amount forecast by analysts.