California demands a special unique California formulation of gasoline Two special CA-specific formulations: winter and summer. Winter gas adds oxygenates, su

California demands a special unique California formulation of gasoline Two special CA-specific formulations: winter and summer. Winter gas adds oxygenates, supposedly reducing certain emissions by 10%. However, it has 10% less energy per unit volume, so you burn 10% more of it. Net effect: more expensive with no real world benefit. Best of all, they blame additional local price rises twice a year on the changeover. It's quite a racket.