The Automobile Association of America says the new E-15 gasoline could be bad for some cars and will confuse customers.
If you haven't heard of E-15 ... and Triple A says 95-percent of people it surveyed have not ... it's a new type of gas blend.
E-15 contains up to 15-percent ethanol.
The motoring corporation says automakers have approved fewer than five percent of vehicles to use it.
Triple A says sustained use could damage both older and newer vehicles by accelerating engine wear, which could void warranties.
The Environmental Protection Agency approved E-15's sale in June, but Triple-A wants the sales stopped until regulators can do a better job educating the public.