The American Petroleum Institute said Friday U.S. demand dropped to an almost four-year low in July, taking the wind out of last week's modest rally.
West Texas Intermediate crude oil for September delivery, above $97 early in the day, slid to $95.97 per barrel on the New York Mercantile Exchange.
Natural gas lost 0.1 cents to $2.775 per million British thermal units.
Home heating oil gained 0.4 cents to $3.0935.
Reformulated blendstock gasoline climbed a 0.1 cent to reach $3.0318 a gallon.
At the pump, the average price for a gallon of regular unleaded gasoline was unchanged from Sunday at $3.20 per gallon, AAA reported.