Shelly Shugars, a training director from Tivoli, N.Y., bought a new 2012 Subaru Impreza Sport hatchback and had her first oil change done on schedule when it hit its first 3,000 miles. But since that oil change, she says she has been adding a quart of oil every 800 to 1,000 miles. Shugars says her Subaru dealer told her that her car’s oil consumption is normal, although the automaker offered her $500 for her trouble. Rebuilding the engine to fix the problem would cost far more.