HOUSTON, April 26 (Reuters) - U.S. gasoline futures rallied to their highest since August on Tuesday and boosted refinery margins after a flurry of Gulf Coast refinery unit outages, buying from Venezuela and a reported drop in New York inventories.
The U.S. gasoline crack spread 1RBc1-CLc1 rose as high as $22.55 early in the day before retreating later to $22.32, up about 3 percent from Monday's finish. The May RBOB contract , which expires on Friday, also rose more than 3.5 percent to $1.5660 per gallon.
Traders said the rise, which spread throughout the oil complex, stemmed largely from an early report from energy intelligence firm Genscape of a 600,000-barrel draw in East Coast gasoline stocks last week.
"It's pretty much a seasonal draw" on rising demand and sellers unloading winter-grade barrels as the New York market switches to summer grade, Genscape analyst Dylan White said.
New York Harbor F5 RBOB spot gasoline differentials climbed about 1.5 cents per gallon to a penny discount to May RBOB as well, traders said.
As of April 15, the East Coast region's gasoline stocks reached 65.1 million barrels, down nearly 10 percent from a 26-year high of 72.2 million barrels in February.
In addition, Venezuela's state-run oil company launched a tender for a 300,000-barrel cargo of catalytic naphtha, a building block for gasoline, for May delivery, further fueling the bump in gasoline futures and margins.
Another factor was the string of gasoline-oriented refinery unit outages - planned and unplanned - in the U.S. Gulf Coast market, according to a Reuters review.
Overall, about 3.1 percent of crude distillation capacity was out, along with nearly 5 percent of vacuum distillation capacity, 2.2 percent of fluid catalytic cracking and 7 percent of delayed coking capacity.
That includes a shut FCC unit at Royal Dutch Shell's 316,000 barrels per day Deer Park, Texas, refinery, and less output from LyondellBasell Industries' 263,776 bpd Houston refinery where a fire damaged a coker April 8.
U.S Gulf Coast cash gasoline differentials also rose on Tuesday, but traders attributed those gains to pipeline scheduling more than regional outages.
Tuesday was the deadline for the last cycles to trade versus May RBOB to be scheduled to move on the Colonial Pipeline, a major fuel artery that links the Gulf Coast with the U.S. Northeast. (Reporting by Kristen Hays, Erwin Seba and Marianna Parraga in Houston, Jarrett Renshaw and Jessica Resnick-Ault in New York; editing by Josephine Mason and Marguerita Choy)