Crude oil for October delivery hit an intraday high of $74.24 a barrel in electronic trading on Globex.
The new front-month contract was last up $1.17, or 1.6%, at $74.08 a barrel.
The U.S. dollar retreated Friday, erasing an earlier rise versus the euro after an influential survey of purchasing managers indicated the single-currency region was poised to return to growth in the third quarter.
The dollar index (DXY 77.97, -0.41, -0.53%) , which tracks the greenback against a trade-weighted basked of six major currencies, recently traded at 77.983, down from 78.330 late Thursday. See Currencies.
Dollar weakness typically boosts dollar-denominated commodities such as oil and gold, because it makes them cheaper for holders of other currencies.
Natural-gas prices extend slide
September natural gas futures extended their decline after ending at a seven-year low in the previous session.
Natural-gas prices were last down 5.60 cents, or 1.9%, to $2.889 per million British thermal units on Globex.
"The market continues to be dominated by short-selling based on speculation that storage capacities will be exhausted by autumn," wrote analysts at Commerzbank in a note to clients.
Almost three months before the end of the inventory build-up cycle, U.S. natural-gas storage facilities are already utilized by about 80%, according to Commerzbank.
"Hence, the potential for a price recovery in natural gas is limited, despite the low price level and the attractive valuation relative to crude oil," the analysts wrote.
Natural-gas prices slumped 5.6% Thursday to end at $2.945 per million British thermal units on the New York Mercantile Exchange after the government reported that working gas in storage rose 52 billion cubic feet to about 3.2 trillion cubic feet during the week ended last Friday. See full story.
In other energy trading on Friday, September reformulated gasoline rose 1.78 cents, or 0.9%, to $2.00 a gallon and September heating oil gained 2.36 cents, or 1.3%, to $1.9088 a gallon.