By EconMatters Exxon Mobil Corp. (XOM), the world’s biggest energy company by market cap, said its 4Q profit rose to a five-year high boosted by its refining arm from growing supplies of cheap U.S. oil.  However, Delta Airlines (DAL) can’t tell a similar success story with its newly acquired refinery.     Delta paid $150 million fora Phillips 66 refineryin Trainer PA last May aiming to save $300 million a year in future fuel costs.  At the time, many analysts see this acquisition as a smart fuel hedge move by Delta.  However, as Ipreviously discussed, since, ... Read More