Modified Gas Formulas

Arizona intends to switch on new gasoline formulas in order to ensure plentiful supply and competitive prices.

Currently, Arizona uses a unique winter blend that few refineries make. During the summer, Arizona shares essentially the same formula as California, but it will soon ban the key ingredient in the gasoline, methyl-tertiary-butyl ether (MTBE).

MTBE is used to reduce ozone and carbon dioxide. The additive increases the octane level, causing engines to burn cleaner.

Arizona relies on California producers for 75 to 80% of its supply of gasoline during the entire year.


The state is eyeing the ethanol blend that will produce a slightly higher concentration of volatile organic compounds that lead to the formation of hazardous ozone.