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(Adds quotes, detail on differential highs and refineryoutages)
By Kristen Hays
HOUSTON, Aug 12 (Reuters) - Chicago cash gasolinedifferentials hit their highest since 2008 this week on theprospect of a month-long shutdown of the top crude unit at BPPlc's Indiana refinery, the largest in the region,traders said on Wednesday.
While the market talked up the premium of Chicago wholesalegasoline to a range of bids and offers that were 75 cents to 80cents over September RBOB futures on the New YorkMercantile Exchange on Wednesday, traders said no deals wereseen. Instead, players sat back after a flurry on Tuesday thatpushed differentials to a 65-cent premium - up from a 2.5-centdiscount to futures on Friday.
"No one wants to be stupid. No one wants to be the guy thatbuys the high," a Midwest trader said.
The trader said the 65-cent premium is the highest since2008, when a shutdown at the same refinery in Whiting, Indiana,sent differentials to $1.40 over NYMEX RBOB.
"That lasted a week," he said.
Cash gasoline in the Group Three market rose as well,trading at a 30-cent premium to futures on Wednesday - up 35cents from Friday.
While the shutdown of the biggest crude distillation unit atBP's 413,500 barrels-per-day (bpd) Whiting refinery gave theMidwest markets their biggest jolt, other factors played a partas well, traders said.
U.S. government data on Wednesday showed a notable905,000-barrel draw in Midwest gasoline stocks last week.
Marathon Petroleum Corp has shut units for 10 weeksof planned work at its 210,000 bpd refinery in Robinson,Illinois - a major Chicago market supplier.
Marathon also began restarting units at its 240,000 bpdrefinery in Catlettsburg, Kentucky, over the weekend after aweek-long outage stemming from a power substation fire.
Valero Energy Corp on Thursday planned to restartthe hydroplex at its 180,000 bpd refinery in Memphis, Tennessee,which has been down for more than a week, cutting the plant'soutput. The hydroplex combines gasoline feedstock hydrotreatingwith production of octane-boosting gasoline components.
And planned work is slated for several Midwest refineries inSeptember and October, including Phillips 66's 336,000 bpdjoint-venture plant in Wood River, Illinois next month - also amajor Chicago market supplier.
Traders were unsure how long differentials would hover atWednesday's levels, weighing the restarts at Catlettsburg andMemphis against upcoming fall maintenance work.
"Hype sells better than reality," a trader said. "It willfind a value."
(Reporting by Kristen Hays; Editing by James Dalgleish andAndrew Hay)
