Somewhere in the Southeast United States is a quick-lube operator who feels caught between a hammer and an anvil. From one side, he is getting pounded by motor oil costs, which have risen steeply for two years. Last months increase was another whopper. His supplier, BP Castrol, was scheduled to hike bulk prices for conventional passenger car oil by 60 cents per gallon. Prices for synthetic oils were going up 94 cents.