U.S. Gulf Coast oils strengthened after the discount for West Texas Intermediate to Brent crude widened past $20 a barrel, the largest gap in four months.

The difference between the benchmarks widened 22 cents to $20.08 at settlement in New York based on September prices. When Brent rises at a faster pace than WTI, as it did today, that typically strengthens the value of U.S. grades competing with foreign oils priced against the European benchmark.

Heavy Louisiana Sweet’s premium to the U.S. benchmark increased $2.35 to $18.60 a barrel at 2:06 p.m. in New York, according to data compiled by Bloomberg. Light Louisiana Sweet increased $2 to $19 over WTI.

Poseidon’s premium added $2.50 to $13.85, while Southern Green Canyon increased $1.85 to $12.50 a barrel over WTI. Mars Blend’s premium gained $2.60 to $14.10.

The premium for Thunder Horse, a sour crude with lower sulfur content than Mars, Poseidon and Southern Green Canyon, widened $1.65 to $16.50.

Syncrude gained 75 cents to $5.25 a barrel over WTI. Syncrude is a synthetic oil upgraded from tar-like bitumen in Alberta into refinery-ready crude.

Western Canada Select’s discount narrowed 55 cents to $11.75 a barrel below WTI, the smallest gap since Dec. 5. Bakken oil’s discount narrowed $1.25 to $1 a barrel below the U.S. benchmark.

To contact the reporter on this story: Aaron Clark in New York at aclark27@bloomberg.net

To contact the editor responsible for this story: Dan Stets at dstets@bloomberg.net